Code No: 07A10201 Set No. 1
I B.Tech Supplimentary Examinations, Aug/Sep 2008
BASIC ELECTRICAL AND ELECTRONICS ENGINEERING
(Bio-Technology)
Time: 3 hours Max Marks: 80
Answer any FIVE Questions
All Questions carry equal marks
⋆ ⋆ ⋆ ⋆ ⋆
1. Three identical coils having a resistance of 10 and an inductance of 0.05 H each,
are connected in star across a 3 phase, 400 V, 50 Hz balanced supply. Calculate
the line current and the power consumed. What will be the readings of the two
watt meters connected to measure the total power? [16]
2. With neat sketch explain the magnetisation characteristics of dc shunt generator.
Also explain how to find Rc and Nc. [16]
3. Justify the necessity of controlling torque in indicating instruments. Discuss the
various methods of producing the same. Compare them. [16]
4. What is a zener diode? Draw the equivalent circuit of an ideal zener in the break-
down region. Why is zener diode used as a voltage regulator? [16]
5. With neat diagram and characteristic curves, explain the operation of JFET. [16]
6. (a) Draw the frequency response of a single stage RC coupled amplifier and explain
the reason for its variable slopes . [10]
(b) If the upper cut off frequency of a single stage RC coupled amplifier is 100 KHz,
what is the overall upper cut off frequency if five such stages are connected.[6]
7. Draw one practical circuit each for:
(a) voltage series feedback.
(b) voltage shunt feedback and justify. [16]
8. (a) Explain: ‘State Assignment’ in Asynchronous sequential machine. [6]
(b) Design a JK Flip Flop asynchronous circuit with two inputs X1 and a X2 and
a single output, X. X=1 if and only if the same input variable changes two or
more times consequently. The circuit should be hazard free. [10]
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Code No: 07A10201 Set No. 2
I B.Tech Supplimentary Examinations, Aug/Sep 2008
BASIC ELECTRICAL AND ELECTRONICS ENGINEERING
(Bio-Technology)
Time: 3 hours Max Marks: 80
Answer any FIVE Questions
All Questions carry equal marks
⋆ ⋆ ⋆ ⋆ ⋆
1. A circuit consisting of three resistances 12 18 and 36 respectively joined in
parallel is connected in series with a fourth resistance. The whole circuit is applied
with 60V and it is found that the power dissipated in the 12 resistor is 36 W.
Determine the value of the fourth resistance and the total power dissipated in the
circuit. [16]
2. (a) Discuss the various three phase transformer groups and their significance. [12]
(b) Compare the commonly used three phase connections. [4]
3. What is the function of damping system in an indicating instruments? Explain
with necessary circuit diagram the methods of producing the damping toque in an
indicating instruments? [16]
4. What is Hall effect and what is are applications? [16]
5. (a) Which biasing method provides more stabilization amongst the three types of
biasing methods? Why?
(b) Explain any one method of biasing a single stage BJT amplifier? [16]
6. Draw the circuit diagram of a transformer coupled push pull class B - power am-
plifier and explain its operation. [16]
7. (a) Explain Colpitt Oscillator operation.
(b) Discuss briefly about the properties of Quartz crystal. Draw the electrical
equivalent circuit of crystal and explain. [16]
8. What are the applications of Gay code? Discuss how Hamming code can be used
for correcting a single over on a four list message (BCD data). [16]
⋆ ⋆ ⋆ ⋆ ⋆
1 of 1
Code No: 07A10201 Set No. 3
I B.Tech Supplimentary Examinations, Aug/Sep 2008
BASIC ELECTRICAL AND ELECTRONICS ENGINEERING
(Bio-Technology)
Time: 3 hours Max Marks: 80
Answer any FIVE Questions
All Questions carry equal marks
⋆ ⋆ ⋆ ⋆ ⋆
1. (a) State Ohm’s law and Kirchoff’s voltage law. [6]
(b) Find the potential difference VAB in the circuit shown Figure 1b using Kirchoffs
laws. [10]
Figure 1b
2. With neat sketch explain the magnetisation characteristics of dc shunt generator.
Also explain how to find Rc and Nc. [16]
3. (a) Compare between spring and gravity control. [8]
(b) Explain with neat sketch the air friction damping. [8]
4. (a) Give the energy band description of conductors, semiconductors and insula-
tors.
(b) What do you understand by intrinsic and extrinsic semiconductors? [8+8]
5. Analyse BJT voltage divider bias configuration. [16]
6. Explain in detail the frequency response of RC coupled amplifier. [16]
7. A Hartley oscillator is designed with L1 = 2mH, L2 = 20μH and a variable capac-
itance. Determine the range of capacitance values is the frequency of oscillation is
varied from 2050 KHz to 3050 KHz. [16]
8. (a) Realize the following function using 8:1 multiplexer. f (A, B, C, D) = ( 0,
3, 5, 6, 9, 10, 12, 15).
(b) Implement a full subtractor using NAND gates? [16]
⋆ ⋆ ⋆ ⋆ ⋆
1 of 1
Code No: 07A10201 Set No. 4
I B.Tech Supplimentary Examinations, Aug/Sep 2008
BASIC ELECTRICAL AND ELECTRONICS ENGINEERING
(Bio-Technology)
Time: 3 hours Max Marks: 80
Answer any FIVE Questions
All Questions carry equal marks
⋆ ⋆ ⋆ ⋆ ⋆
1. Calculate the equivalent resistance of the combination of resistors shown in figure
1 and also calculate the source current. [16]
Figure 1
2. Describe the principle of operation of single phase induction motor using capacitor.
Draw the circuit and phasor diagram. [16]
3. (a) Compare between spring and gravity control. [8]
(b) Explain with neat sketch the air friction damping. [8]
4. What is Hall effect and what is are applications? [16]
5. With neat diagram and characteristic curves, explain the operation of JFET. [16]
6. Draw the class B push pull emitter follower circuit and explain its operation. [16]
7. A Hartley oscillator is designed with L1 = 2mH, L2 = 20μH and a variable capac-
itance. Determine the range of capacitance values is the frequency of oscillation is
varied from 2050 KHz to 3050 KHz. [16]
8. (a) Realize the following function using 8:1 multiplexer. f (A, B, C, D) = ( 0,
3, 5, 6, 9, 10, 12, 15).
(b) Implement a full subtractor using NAND gates? [16]
⋆ ⋆ ⋆ ⋆ ⋆
1 of 1
Showing posts with label BASIC ELECTRICAL AND ELECTRONIC ENGINEERING(BEEE). Show all posts
Showing posts with label BASIC ELECTRICAL AND ELECTRONIC ENGINEERING(BEEE). Show all posts
Saturday, November 22, 2008
ELECTRICAL AND ELECTRONICS ENGINEERING-SUPPLY 2K8
Code No: RR12302 Set No. 1
I B.Tech Supplimentary Examinations, Aug/Sep 2008
ELECTRICAL AND ELECTRONICS ENGINEERING
(Bio-Technology)
Time: 3 hours Max Marks: 80
Answer any FIVE Questions
All Questions carry equal marks
⋆ ⋆ ⋆ ⋆ ⋆
1. (a) A voltage wave form shown in the figure 1a is applied to a pure resistance of
40 .
Sketch the wave form of the current passing through the resistance.
Figure 1a
(b) Solve the network shown in the figure 1b below for currents in the various
resistors.
[6+10]
Figure 1b
2. (a) Explain the constructional details of a synchronous machine giving the reasons
for making two types of rotors.
(b) Explain auxiliary motor starting of synchronous motors. [6+10]
3. (a) For the network shown in the figure 3(a)i determine the range of RL and IL
that will result in VRL being maintained at 10 V.
1 of 3
Code No: RR12302 Set No. 1
i. Determine the maximum Wattage rating of the diode.
Figure 3(a)i
ii. The reverse saturation current of the diode is 1 μA. Its peak inverse Volt-
age is 500V. Find ri, Vo that PIV is not exceeded. show in figure 3(a)ii &
figure 3(a)ii
Figure 3(a)ii
Figure 3(a)ii
2 of 3
Code No: RR12302 Set No. 1
4. (a) What do you mean by regulation and explain how a full wave rectifier is used
for it.
(b) Compare center tapped transformer and ordinary transformer. What is the
difference in their construction?
(c) Mention the applications of rectifiers in detail. [6+5+5]
5. (a) Define different stability factors of biasing circuits using BJT.
(b) List out different transistor biasing methods and compare their merits and
demerits.
(c) Write short notes on
i. Thermal runaway
ii. Early effect [6+6+4]
6. (a) Draw the circuit diagram of an emitter follower circuit and its h-parameter
model.
(b) For the given component values Rs = 1K, RL = 3 K and for the given h-
parameters hfe = 100, hie = 2K, hre = 2.5 × 10−4, hoe = 10μA/V. Calculate
AI , RI , Avs and R0. [6+10]
7. (a) What kind of feedback is incorporated in the Wien bridge oscillator circuit
and why?
(b) In a colpitts oscillator using FET, the frequency of oscillations is observed to
be 2.5 MHz. Oscillator uses L=10 μH, C1 = 0.02 μF. Find
i. the value of C2
ii. If L is doubled the new value of frequency oscillations.
(c) Explain about the applications of OP-AMPs. [4+6+6]
8. (a) Realize NAND gate using minimum number of NOR gates.
(b) Explain the principle of basic shift registers.
(c) Distinguish between asynchronous and synchronous counters.
(d) Distinguish between Ring and Twisted Ring counters. [4+4+4+4]
⋆ ⋆ ⋆ ⋆ ⋆
3 of 3
Code No: RR12302 Set No. 2
I B.Tech Supplimentary Examinations, Aug/Sep 2008
ELECTRICAL AND ELECTRONICS ENGINEERING
(Bio-Technology)
Time: 3 hours Max Marks: 80
Answer any FIVE Questions
All Questions carry equal marks
⋆ ⋆ ⋆ ⋆ ⋆
1. (a) State and explain Kirchoff’s Law. [6M]
(b) Calculate the current through the resistance of 5 in the specified direction
as shown in the figure 1b [10M]
Figure 1b
2. (a) Explain the process of voltage build up in a self-excited D.C machine.
(b) List out the various conditions to be satisfied for voltage build up process in
a self-excited machine, and write down remedies if the conditions fail. [8+8]
3. (a) Prove that the Fermi level for p-type semiconductor is given by
EF = EV + KT ln NV
NA .
(b) In a p-type semiconductor, if the concentration of acceptor atoms is increased
by a factor 10, find the shift in the position of Fermi level. Assume KT=0.03
ev.
[10+6]
4. (a) The half wave rectifier shown in the figure 4a is fed with a sinusoidal voltage
V=20 sin100t.
i. Sketch the output waveform.
ii. Determine the DC output voltage assuming ideal diode behaviour.
iii. Repeat the calculations assuming the simplified diode (silicon) model.
1 of 3
Code No: RR12302 Set No. 2
Figure 4a
(b) Draw the circuit diagram of full wave rectifier having two diodes and explain
its operation. [8+8]
5. (a) Sketch the input and output characteristics of CB configuration for an n-p-n
transistor, Explain the shape of the curves qualitatively.
(b) For the circuit in figure 5b shown if α = 0.98 VBE = 0.7 V find R1 in the
circuit for an emitter current of IE = -2 mA. Neglect the reverse saturation
current.
[8+8]
Figure 5b
6. (a) Compare the three transistor amplifier configurations with related to AI , Av,
Ri and R0.
(b) For the circuit shown calculate AI , AV , Ri and R0 using approximate
h-parameter model. Assume hfe = 50, hie = 1100 , hoe = 25 μA/V, hre =
2.5 × 10−4 as shown in the figure 6b. [16]
2 of 3
Code No: RR12302 Set No. 2
Figure 6b
7. Define the following terms with reference to OP-AMPs:
(a) i/p bias current
(b) i/p offset current
(c) open loop gain
(d) i/p off set voltage
(e) o/p offset voltage
(f) CMRR
(g) PSSR
(h) Skew rate. [16]
8. (a) Explain with a block diagram the major blocks of a digital computer.
(b) Implement the following with either NAND or NOR gates. Use only 4 gates
only the normal inputs are available.
F = w′xz + w′yz + x′yz′ + wxy′z.
(c) With a circuit diagram, explain Counter type A to D converter. [4+6+6]
⋆ ⋆ ⋆ ⋆ ⋆
3 of 3
Code No: RR12302 Set No. 3
I B.Tech Supplimentary Examinations, Aug/Sep 2008
ELECTRICAL AND ELECTRONICS ENGINEERING
(Bio-Technology)
Time: 3 hours Max Marks: 80
Answer any FIVE Questions
All Questions carry equal marks
⋆ ⋆ ⋆ ⋆ ⋆
1. (a) Determine the effective resistance between the nodes A and B in the circuit
shown in the figure 1a (all values are in ohms).
Figure 1a
(b) Find the Vc and IL from the circuit shown in Figure 1b under steady state
conditions. [10+6]
Figure 1b
2. (a) Name the various parts of a D.C machine and give the materials used for each
part. Also show the magnetic path.
(b) Explain the principle of operation of D.C motor. [8+8]
3. (a) Prove that the concentration of holes in an intrinsic semiconductor is given by
p = Nve−(EF−EV )/KT .
(b) Prove that for intrinsic semiconductor n2i proportional to T3e−EGO/KT [6+10]
4. (a) The half wave rectifier shown in the figure 4a is fed with a sinusoidal voltage
V=20 sin100t.
i. Sketch the output waveform.
ii. Determine the DC output voltage assuming ideal diode behaviour.
iii. Repeat the calculations assuming the simplified diode (silicon) model.
1 of 3
Code No: RR12302 Set No. 3
Figure 4a
(b) Draw the circuit diagram of full wave rectifier having two diodes and explain
its operation. [8+8]
5. (a) Compare and contrast FET and BJT.
(b) Give the constructional features of JFET and explain its operation with the
help of the drain characteristics.
(c) From the drain characteristics derive mutual characteristic and explain the
shape of the curve qualitatively. [6+6+4]
6. (a) Compare the three transistor amplifier configurations with related to AI , Av,
Ri and R0.
(b) For the circuit shown calculate AI , AV , Ri and R0 using approximate
h-parameter model. Assume hfe = 50, hie = 1100 , hoe = 25 μA/V, hre =
2.5 × 10−4 as shown in the figure 6b. [16]
Figure 6b
7. (a) Explain the operation of an integrator using OP-AMPs.
(b) Distinguish between positive and negative feedbacks.
(c) List out the characteristics of OP-AMP. [6+4+6]
2 of 3
Code No: RR12302 Set No. 3
8. (a) Convert the following numbers:
i. (1431)10 to base 2.
ii. (53.1575)10 to base 2.
(b) Implement AB+C′D′ = F with three NAND gates. Draw the logic circuit.
(c) Prove that the NAND Gate is a universal gate.. [8+4+4]
⋆ ⋆ ⋆ ⋆ ⋆
3 of 3
Code No: RR12302 Set No. 4
I B.Tech Supplimentary Examinations, Aug/Sep 2008
ELECTRICAL AND ELECTRONICS ENGINEERING
(Bio-Technology)
Time: 3 hours Max Marks: 80
Answer any FIVE Questions
All Questions carry equal marks
⋆ ⋆ ⋆ ⋆ ⋆
1. (a) Determine the effective resistance between the nodes A and B in the circuit
shown in the figure 1a (all values are in ohms).
Figure 1a
(b) Find the Vc and IL from the circuit shown in Figure 1b under steady state
conditions. [10+6]
Figure 1b
2. (a) Describe the construction of a 1-phase transformer and principle of operation.
(b) Write about 3-phase transformer connections. [8+8]
3. (a) For the network shown in the figure 3(a)i determine the range of RL and IL
that will result in VRL being maintained at 10 V.
i. Determine the maximum Wattage rating of the diode.
1 of 3
Code No: RR12302 Set No. 4
Figure 3(a)i
ii. The reverse saturation current of the diode is 1 μA. Its peak inverse Volt-
age is 500V. Find ri, Vo that PIV is not exceeded. show in figure 3(a)ii &
figure 3(a)ii
Figure 3(a)ii
Figure 3(a)ii
4. (a) The half wave rectifier shown in the figure 4a is fed with a sinusoidal voltage
2 of 3
Code No: RR12302 Set No. 4
V=20 sin100t.
i. Sketch the output waveform.
ii. Determine the DC output voltage assuming ideal diode behaviour.
iii. Repeat the calculations assuming the simplified diode (silicon) model.
Figure 4a
(b) Draw the circuit diagram of full wave rectifier having two diodes and explain
its operation. [8+8]
5. (a) Draw the emitter characteristic of UJT and explain the shape of the curve
qualitatively. Mention different regions of operations.
(b) Draw the circuit of a relaxation oscillator and explain its operations. Mention
its applications. [8+8]
6. (a) Give the advantages of negative feedback amplifier.
(b) Draw the circuit of a voltage shunt feedback amplifier and explain.
(c) When the negative feedback is applied to an amplifier of gain 100, the overall
gain falls to 50. Calculate
i. the feedback factor ‘β’
ii. If the same feedback factor is maintained, find the value of amplifier gain
required if the overall gain is to be 75. [4+6+6]
7. (a) List out the characteristics of OP-AMPs.
(b) Explain about the concept of ‘Virtual Ground’ in OP-AMPs.
(c) Draw the circuit diagram of emitter coupled differential amplifier and obtain
its DC analysis.. [6+4+6]
8. (a) Realize NAND gate using minimum number of NOR gates.
(b) Explain the principle of basic shift registers.
(c) Distinguish between asynchronous and synchronous counters.
(d) Distinguish between Ring and Twisted Ring counters. [4+4+4+4]
⋆ ⋆ ⋆ ⋆ ⋆
3 of 3
I B.Tech Supplimentary Examinations, Aug/Sep 2008
ELECTRICAL AND ELECTRONICS ENGINEERING
(Bio-Technology)
Time: 3 hours Max Marks: 80
Answer any FIVE Questions
All Questions carry equal marks
⋆ ⋆ ⋆ ⋆ ⋆
1. (a) A voltage wave form shown in the figure 1a is applied to a pure resistance of
40 .
Sketch the wave form of the current passing through the resistance.
Figure 1a
(b) Solve the network shown in the figure 1b below for currents in the various
resistors.
[6+10]
Figure 1b
2. (a) Explain the constructional details of a synchronous machine giving the reasons
for making two types of rotors.
(b) Explain auxiliary motor starting of synchronous motors. [6+10]
3. (a) For the network shown in the figure 3(a)i determine the range of RL and IL
that will result in VRL being maintained at 10 V.
1 of 3
Code No: RR12302 Set No. 1
i. Determine the maximum Wattage rating of the diode.
Figure 3(a)i
ii. The reverse saturation current of the diode is 1 μA. Its peak inverse Volt-
age is 500V. Find ri, Vo that PIV is not exceeded. show in figure 3(a)ii &
figure 3(a)ii
Figure 3(a)ii
Figure 3(a)ii
2 of 3
Code No: RR12302 Set No. 1
4. (a) What do you mean by regulation and explain how a full wave rectifier is used
for it.
(b) Compare center tapped transformer and ordinary transformer. What is the
difference in their construction?
(c) Mention the applications of rectifiers in detail. [6+5+5]
5. (a) Define different stability factors of biasing circuits using BJT.
(b) List out different transistor biasing methods and compare their merits and
demerits.
(c) Write short notes on
i. Thermal runaway
ii. Early effect [6+6+4]
6. (a) Draw the circuit diagram of an emitter follower circuit and its h-parameter
model.
(b) For the given component values Rs = 1K, RL = 3 K and for the given h-
parameters hfe = 100, hie = 2K, hre = 2.5 × 10−4, hoe = 10μA/V. Calculate
AI , RI , Avs and R0. [6+10]
7. (a) What kind of feedback is incorporated in the Wien bridge oscillator circuit
and why?
(b) In a colpitts oscillator using FET, the frequency of oscillations is observed to
be 2.5 MHz. Oscillator uses L=10 μH, C1 = 0.02 μF. Find
i. the value of C2
ii. If L is doubled the new value of frequency oscillations.
(c) Explain about the applications of OP-AMPs. [4+6+6]
8. (a) Realize NAND gate using minimum number of NOR gates.
(b) Explain the principle of basic shift registers.
(c) Distinguish between asynchronous and synchronous counters.
(d) Distinguish between Ring and Twisted Ring counters. [4+4+4+4]
⋆ ⋆ ⋆ ⋆ ⋆
3 of 3
Code No: RR12302 Set No. 2
I B.Tech Supplimentary Examinations, Aug/Sep 2008
ELECTRICAL AND ELECTRONICS ENGINEERING
(Bio-Technology)
Time: 3 hours Max Marks: 80
Answer any FIVE Questions
All Questions carry equal marks
⋆ ⋆ ⋆ ⋆ ⋆
1. (a) State and explain Kirchoff’s Law. [6M]
(b) Calculate the current through the resistance of 5 in the specified direction
as shown in the figure 1b [10M]
Figure 1b
2. (a) Explain the process of voltage build up in a self-excited D.C machine.
(b) List out the various conditions to be satisfied for voltage build up process in
a self-excited machine, and write down remedies if the conditions fail. [8+8]
3. (a) Prove that the Fermi level for p-type semiconductor is given by
EF = EV + KT ln NV
NA .
(b) In a p-type semiconductor, if the concentration of acceptor atoms is increased
by a factor 10, find the shift in the position of Fermi level. Assume KT=0.03
ev.
[10+6]
4. (a) The half wave rectifier shown in the figure 4a is fed with a sinusoidal voltage
V=20 sin100t.
i. Sketch the output waveform.
ii. Determine the DC output voltage assuming ideal diode behaviour.
iii. Repeat the calculations assuming the simplified diode (silicon) model.
1 of 3
Code No: RR12302 Set No. 2
Figure 4a
(b) Draw the circuit diagram of full wave rectifier having two diodes and explain
its operation. [8+8]
5. (a) Sketch the input and output characteristics of CB configuration for an n-p-n
transistor, Explain the shape of the curves qualitatively.
(b) For the circuit in figure 5b shown if α = 0.98 VBE = 0.7 V find R1 in the
circuit for an emitter current of IE = -2 mA. Neglect the reverse saturation
current.
[8+8]
Figure 5b
6. (a) Compare the three transistor amplifier configurations with related to AI , Av,
Ri and R0.
(b) For the circuit shown calculate AI , AV , Ri and R0 using approximate
h-parameter model. Assume hfe = 50, hie = 1100 , hoe = 25 μA/V, hre =
2.5 × 10−4 as shown in the figure 6b. [16]
2 of 3
Code No: RR12302 Set No. 2
Figure 6b
7. Define the following terms with reference to OP-AMPs:
(a) i/p bias current
(b) i/p offset current
(c) open loop gain
(d) i/p off set voltage
(e) o/p offset voltage
(f) CMRR
(g) PSSR
(h) Skew rate. [16]
8. (a) Explain with a block diagram the major blocks of a digital computer.
(b) Implement the following with either NAND or NOR gates. Use only 4 gates
only the normal inputs are available.
F = w′xz + w′yz + x′yz′ + wxy′z.
(c) With a circuit diagram, explain Counter type A to D converter. [4+6+6]
⋆ ⋆ ⋆ ⋆ ⋆
3 of 3
Code No: RR12302 Set No. 3
I B.Tech Supplimentary Examinations, Aug/Sep 2008
ELECTRICAL AND ELECTRONICS ENGINEERING
(Bio-Technology)
Time: 3 hours Max Marks: 80
Answer any FIVE Questions
All Questions carry equal marks
⋆ ⋆ ⋆ ⋆ ⋆
1. (a) Determine the effective resistance between the nodes A and B in the circuit
shown in the figure 1a (all values are in ohms).
Figure 1a
(b) Find the Vc and IL from the circuit shown in Figure 1b under steady state
conditions. [10+6]
Figure 1b
2. (a) Name the various parts of a D.C machine and give the materials used for each
part. Also show the magnetic path.
(b) Explain the principle of operation of D.C motor. [8+8]
3. (a) Prove that the concentration of holes in an intrinsic semiconductor is given by
p = Nve−(EF−EV )/KT .
(b) Prove that for intrinsic semiconductor n2i proportional to T3e−EGO/KT [6+10]
4. (a) The half wave rectifier shown in the figure 4a is fed with a sinusoidal voltage
V=20 sin100t.
i. Sketch the output waveform.
ii. Determine the DC output voltage assuming ideal diode behaviour.
iii. Repeat the calculations assuming the simplified diode (silicon) model.
1 of 3
Code No: RR12302 Set No. 3
Figure 4a
(b) Draw the circuit diagram of full wave rectifier having two diodes and explain
its operation. [8+8]
5. (a) Compare and contrast FET and BJT.
(b) Give the constructional features of JFET and explain its operation with the
help of the drain characteristics.
(c) From the drain characteristics derive mutual characteristic and explain the
shape of the curve qualitatively. [6+6+4]
6. (a) Compare the three transistor amplifier configurations with related to AI , Av,
Ri and R0.
(b) For the circuit shown calculate AI , AV , Ri and R0 using approximate
h-parameter model. Assume hfe = 50, hie = 1100 , hoe = 25 μA/V, hre =
2.5 × 10−4 as shown in the figure 6b. [16]
Figure 6b
7. (a) Explain the operation of an integrator using OP-AMPs.
(b) Distinguish between positive and negative feedbacks.
(c) List out the characteristics of OP-AMP. [6+4+6]
2 of 3
Code No: RR12302 Set No. 3
8. (a) Convert the following numbers:
i. (1431)10 to base 2.
ii. (53.1575)10 to base 2.
(b) Implement AB+C′D′ = F with three NAND gates. Draw the logic circuit.
(c) Prove that the NAND Gate is a universal gate.. [8+4+4]
⋆ ⋆ ⋆ ⋆ ⋆
3 of 3
Code No: RR12302 Set No. 4
I B.Tech Supplimentary Examinations, Aug/Sep 2008
ELECTRICAL AND ELECTRONICS ENGINEERING
(Bio-Technology)
Time: 3 hours Max Marks: 80
Answer any FIVE Questions
All Questions carry equal marks
⋆ ⋆ ⋆ ⋆ ⋆
1. (a) Determine the effective resistance between the nodes A and B in the circuit
shown in the figure 1a (all values are in ohms).
Figure 1a
(b) Find the Vc and IL from the circuit shown in Figure 1b under steady state
conditions. [10+6]
Figure 1b
2. (a) Describe the construction of a 1-phase transformer and principle of operation.
(b) Write about 3-phase transformer connections. [8+8]
3. (a) For the network shown in the figure 3(a)i determine the range of RL and IL
that will result in VRL being maintained at 10 V.
i. Determine the maximum Wattage rating of the diode.
1 of 3
Code No: RR12302 Set No. 4
Figure 3(a)i
ii. The reverse saturation current of the diode is 1 μA. Its peak inverse Volt-
age is 500V. Find ri, Vo that PIV is not exceeded. show in figure 3(a)ii &
figure 3(a)ii
Figure 3(a)ii
Figure 3(a)ii
4. (a) The half wave rectifier shown in the figure 4a is fed with a sinusoidal voltage
2 of 3
Code No: RR12302 Set No. 4
V=20 sin100t.
i. Sketch the output waveform.
ii. Determine the DC output voltage assuming ideal diode behaviour.
iii. Repeat the calculations assuming the simplified diode (silicon) model.
Figure 4a
(b) Draw the circuit diagram of full wave rectifier having two diodes and explain
its operation. [8+8]
5. (a) Draw the emitter characteristic of UJT and explain the shape of the curve
qualitatively. Mention different regions of operations.
(b) Draw the circuit of a relaxation oscillator and explain its operations. Mention
its applications. [8+8]
6. (a) Give the advantages of negative feedback amplifier.
(b) Draw the circuit of a voltage shunt feedback amplifier and explain.
(c) When the negative feedback is applied to an amplifier of gain 100, the overall
gain falls to 50. Calculate
i. the feedback factor ‘β’
ii. If the same feedback factor is maintained, find the value of amplifier gain
required if the overall gain is to be 75. [4+6+6]
7. (a) List out the characteristics of OP-AMPs.
(b) Explain about the concept of ‘Virtual Ground’ in OP-AMPs.
(c) Draw the circuit diagram of emitter coupled differential amplifier and obtain
its DC analysis.. [6+4+6]
8. (a) Realize NAND gate using minimum number of NOR gates.
(b) Explain the principle of basic shift registers.
(c) Distinguish between asynchronous and synchronous counters.
(d) Distinguish between Ring and Twisted Ring counters. [4+4+4+4]
⋆ ⋆ ⋆ ⋆ ⋆
3 of 3
ELECTRICAL AND ELECTRONICS ENGINEERING-AUG 2K7
Code No: RR12302 Set No. 1
I B.Tech Supplimentary Examinations, Aug/Sep 2007
ELECTRICAL AND ELECTRONICS ENGINEERING
(Bio-Technology)
Time: 3 hours Max Marks: 80
Answer any FIVE Questions
All Questions carry equal marks
⋆ ⋆ ⋆ ⋆ ⋆
1. (a) State and explain Kirchoff’s Law. [6M]
(b) Calculate the current through the resistance of 5 in the specified direction
as shown in the figure 1b [10M]
Figure 1b
2. (a) Give the constructional features of “CORE” and “Shell” types of transformers,
and give the advantages and disadvantages of each type.
(b) A 5 KVA, 2300 / 230 V, 50 Hz transformer was tested for the iron loss with
normal excitation and copper losses at full load, and these were found to be
40 Watts and 112 Watts respectively. Calculate efficiency of the transformer
at
i. full load.
ii. half full load.
Assume the power factor of the load as 0.8. [8+8]
3. (a) For the network shown in the figure 3(a)i determine the range of RL and IL
that will result in VRL being maintained at 10 V.
i. Determine the maximum Wattage rating of the diode.
1 of 4
Code No: RR12302 Set No. 1
Figure 3(a)i
ii. The reverse saturation current of the diode is 1 μA. Its peak inverse Volt-
age is 500V. Find ri, Vo that PIV is not exceeded. show in figure 3(a)ii &
figure 3(a)iii
Figure 3(a)ii
Figure 3(a)iii
4. (a) The half wave rectifier shown in the figure 4a is fed with a sinusoidal voltage
2 of 4
Code No: RR12302 Set No. 1
V=20 sin100t.
i. Sketch the output waveform.
ii. Determine the DC output voltage assuming ideal diode behaviour.
iii. Repeat the calculations assuming the simplified diode (silicon) model.
Figure 4a
(b) Draw the circuit diagram of full wave rectifier having two diodes and explain
its operation. [8+8]
5. (a) Draw the circuit of transistor (p-n-p) in the CE configuration, sketch the
family of input and output characteristics and explain the shape of the curves
qualitatively.
(b) For the circuit in figure 5b shown find R. Neglect the reverse saturation current.
Assume silicon transistor is used.
[8+8]
Figure 5b
6. (a) Draw the circuit of a transformer coupled amplifier and explain its operations.
(b) Draw the circuit of a class B push-pull amplifier and derive expression for the
output power. [8+8]
7. (a) Explain the operation of an integrator using OP-AMPs.
(b) Distinguish between positive and negative feedbacks.
(c) List out the characteristics of OP-AMP. [6+4+6]
8. (a) Explain the principle of Half-adder. Draw various implementations of sum
and carry of Half-adder.
(b) Implement AND and OR gate using discrete components.
3 of 4
Code No: RR12302 Set No. 1
(c) How do you convert JK-flip-flop to T and D flip-flops. . [6+6+4]
⋆ ⋆ ⋆ ⋆ ⋆
4 of 4
Code No: RR12302 Set No. 2
I B.Tech Supplimentary Examinations, Aug/Sep 2007
ELECTRICAL AND ELECTRONICS ENGINEERING
(Bio-Technology)
Time: 3 hours Max Marks: 80
Answer any FIVE Questions
All Questions carry equal marks
⋆ ⋆ ⋆ ⋆ ⋆
1. (a) Derive the voltage current relations (between line and phase) values for a star
and delta connected systems.
(b) A 3-phase, 4 wire 208V system supplies power to a star connected load each
arm with impedance equal to (17.32 − j10) ohms (per phase) find the line
currents, power consumed, and the power factor of the load. [8+8]
2. (a) Explain the constructional details of a synchronous machine giving the reasons
for making two types of rotors.
(b) Explain auxiliary motor starting of synchronous motors. [6+10]
3. (a) Draw the V-I characteristics of Zener diode and explain.
(b) For the Zener voltage regulator shown in the figure 3b determine the range
of RL and IL that gives a stabilized voltage of 10 V. What should be wattage
rating of the diode?
Figure 3b
(c) Explain how Zener diode acts as voltage regulator. [4+8+4]
4. (a) The half wave rectifier shown in the figure 4a is fed with a sinusoidal voltage
V=20 sin100t.
i. Sketch the output waveform.
ii. Determine the DC output voltage assuming ideal diode behaviour.
iii. Repeat the calculations assuming the simplified diode (silicon) model.
1 of 2
Code No: RR12302 Set No. 2
Figure 4a
(b) Draw the circuit diagram of full wave rectifier having two diodes and explain
its operation. [8+8]
5. (a) Compare the merits and drawbacks of FET and BJT.
(b) Sketch the basic structure of an n-channel JFET.
(c) Define the pinch off voltage VP and sketch the depletion region before and
after pinch-off and explain the reason. [6+4+6]
6. (a) Give the advantages of negative feedback amplifier.
(b) Draw the circuit of a voltage shunt feedback amplifier and explain.
(c) When the negative feedback is applied to an amplifier of gain 100, the overall
gain falls to 50. Calculate
i. the feedback factor ’β’
ii. If the same feedback factor is maintained, find the value of amplifier gain
required if the overall gain is to be 75. [4+6+6]
7. (a) With the help of neat circuit diagram, explain the following applications of
OP-AMP
i. Multiplier
ii. differentiator
iii. Subtractor.
(b) Design a scaling adder circuit using OP-AMP, to give the output voltage
Vo = −(3V 1 +4V 2 +5V 3),where V1, V2 and V3 are the input voltages given to
the circuit. [10+6]
8. (a) Realize NAND gate using minimum number of NOR gates.
(b) Explain the principle of basic shift registers.
(c) Distinguish between asynchronous and synchronous counters.
(d) Distinguish between Ring and Twisted Ring counters. [4+4+4+4]
⋆ ⋆ ⋆ ⋆ ⋆
2 of 2
Code No: RR12302 Set No. 3
I B.Tech Supplimentary Examinations, Aug/Sep 2007
ELECTRICAL AND ELECTRONICS ENGINEERING
(Bio-Technology)
Time: 3 hours Max Marks: 80
Answer any FIVE Questions
All Questions carry equal marks
⋆ ⋆ ⋆ ⋆ ⋆
1. (a) Derive an equation for the total power consumed in a three ? phase circuit.
Will it depend on the type of load connected?
(b) Three identical impedances 106 53.10 ohm are connected in delta to a 3-phase,
240 volt balanced supply. Find the line currents and power consumed. [8+8]
2. (a) Give the various power stages of a 3-phase induction motor(the various stages
from the input to induction motor to output) and explain each stage.
(b) Explain principle of operation of three − phase induction motor. [8+8]
3. (a) Give the specifications of Zener diode.
(b) Explain the terms:
i. Space-charge region
ii. Transition region.
iii. Barrier potential.
iv. Donar impurities,
v. Acceptor impurities. [4+12]
4. (a) The half wave rectifier shown in the figure 4a is fed with a sinusoidal voltage
V=20 sin100t.
i. Sketch the output waveform.
ii. Determine the DC output voltage assuming ideal diode behaviour.
iii. Repeat the calculations assuming the simplified diode (silicon) model.
Figure 4a
(b) Draw the circuit diagram of full wave rectifier having two diodes and explain
its operation. [8+8]
1 of 3
Code No: RR12302 Set No. 3
5. (a) Draw the circuit of transistor (p-n-p) in the CE configuration, sketch the
family of input and output characteristics and explain the shape of the curves
qualitatively.
(b) For the circuit in figure 5b shown find R. Neglect the reverse saturation current.
Assume silicon transistor is used.
[8+8]
Figure 5b
6. (a) Draw the h-parameter small signal low-frequency BJT model and what are
the dimensions of each parameter.
(b) Draw the approximate h-parameter model for common collector configuration
and derive expressions for current gain, Input Resistance, voltage gain and
output resistance. [6+10]
7. (a) Draw the circuit diagram of Wien bridge oscillator using BJT. Show that the
gain of the amplifier must be at least 3 for the oscillations to occur.
(b) For the fixed-bias Ge transistor, n-p-n type, the junction voltages at satura-
tion and cutoff one in active region, may be assumed to zero. This circuit
operate properly over the temperature range -50 oC to 75 oC and to just start
malfunctioning at these extremes. The various circuit specifications are: VCC
= 4.5V, VBB = 3volts, hfe=40 at -50 oC, and hfe=60 at 75 oC, ICBO = 4
μA at 25 oC and doubles every 10 oC. Collector current is 10 μA. Design the
values of Rc1, R1 and R2. [8+8]
8. (a) Explain the following switching circuit in binary logic notation as shown in
the figure8a
Figure 8a
(b) Define a register. Construct a shift register using S-R flip-flops and explain
its operation.
(c) Convert the following numbers:
i. (101101. 101101)2 decimal number
2 of 3
Code No: RR12302 Set No. 3
ii. (5345)10 to binary number. [4+6+6]
⋆ ⋆ ⋆ ⋆ ⋆
3 of 3
Code No: RR12302 Set No. 4
I B.Tech Supplimentary Examinations, Aug/Sep 2007
ELECTRICAL AND ELECTRONICS ENGINEERING
(Bio-Technology)
Time: 3 hours Max Marks: 80
Answer any FIVE Questions
All Questions carry equal marks
⋆ ⋆ ⋆ ⋆ ⋆
1. (a) Define resistance.
(b) State and explain Ohms Law.
(c) Find out the equivalent resistance of the following circuit between the points
A and B (all values are in ohms) as shown in the figure 1c [2+4+4]
Figure 1c
(d) Find the impedance between ‘X’ and ‘Y’ points of the figure 1d shown. [6]
Figure 1d
2. (a) Discuss the classification of D.C generators with suitable diagrams, and give
the practical applications of each generator.
1 of 4
Code No: RR12302 Set No. 4
(b) A 10 kW shunt generator supplies load at a terminal voltage of 200 volts.
The shunt field resistance is 100 ohms and armature resistance is 0.1 ohm.
Calculate the e.m.f induced in the generator. [8+8]
3. (a) For the network shown in the figure 3(a)i determine the range of RL and IL
that will result in VRL being maintained at 10 V.
i. Determine the maximum Wattage rating of the diode.
Figure 3(a)i
ii. The reverse saturation current of the diode is 1 μA. Its peak inverse Volt-
age is 500V. Find ri, Vo that PIV is not exceeded. show in figure 3(a)ii &
figure 3(a)iii
Figure 3(a)ii
2 of 4
Code No: RR12302 Set No. 4
Figure 3(a)iii
4. (a) Draw the circuit diagram of half wave rectifier and explain its operation.
(b) A half wave rectifier is fed by 220 V, 50 Hz via a step down transformer of
turns ratio 11:1 find
i. the output DC and
ii. peak inverse voltage under no load condition. [8+8]
5. (a) Sketch a family of drain characteristics of JFET and explain the shape of the
curves qualitatively.
(b) Obtain transfer characteristic of JFET from its drain characteristics and ex-
plain the shape of curves qualitatively.
(c) How a JFET can be used as voltage variable resistor (VVR)? Explain.[4+6+6]
6. (a) Compare the three transistor amplifier configurations with related to AI , Av,
Ri and R0.
(b) For the circuit shown calculate AI , AV , Ri and R0 using approximate
h-parameter model. Assume hfe = 50, hie = 1100 , hoe = 25 μA/V, hre =
2.5 × 10−4 as shown in the figure 6b.
3 of 4
Code No: RR12302 Set No. 4
Figure 6b
7. (a) Explain the principle of operation of self-bias binary circuit.
(b) A FET phase shift oscillator has gm=500 μs, and rd = 30 k. The feedback
resistance is 100 k, and the capacitor value is 64.97 pF. Calculate the fre-
quency of oscillations and the value of RD. Draw the corresponding circuit
diagram.
[8+8]
8. (a) Realize Exclusive OR gate using minimum number of NAND gates.
(b) Realize SR flip-flop using NAND gates.
(c) Explain the principle of decade counter and realize it using JK-flip-flops.
(d) Realize exclusive OR gate using basic gates. [4+4+4+4]
⋆ ⋆ ⋆ ⋆ ⋆
4 of 4
I B.Tech Supplimentary Examinations, Aug/Sep 2007
ELECTRICAL AND ELECTRONICS ENGINEERING
(Bio-Technology)
Time: 3 hours Max Marks: 80
Answer any FIVE Questions
All Questions carry equal marks
⋆ ⋆ ⋆ ⋆ ⋆
1. (a) State and explain Kirchoff’s Law. [6M]
(b) Calculate the current through the resistance of 5 in the specified direction
as shown in the figure 1b [10M]
Figure 1b
2. (a) Give the constructional features of “CORE” and “Shell” types of transformers,
and give the advantages and disadvantages of each type.
(b) A 5 KVA, 2300 / 230 V, 50 Hz transformer was tested for the iron loss with
normal excitation and copper losses at full load, and these were found to be
40 Watts and 112 Watts respectively. Calculate efficiency of the transformer
at
i. full load.
ii. half full load.
Assume the power factor of the load as 0.8. [8+8]
3. (a) For the network shown in the figure 3(a)i determine the range of RL and IL
that will result in VRL being maintained at 10 V.
i. Determine the maximum Wattage rating of the diode.
1 of 4
Code No: RR12302 Set No. 1
Figure 3(a)i
ii. The reverse saturation current of the diode is 1 μA. Its peak inverse Volt-
age is 500V. Find ri, Vo that PIV is not exceeded. show in figure 3(a)ii &
figure 3(a)iii
Figure 3(a)ii
Figure 3(a)iii
4. (a) The half wave rectifier shown in the figure 4a is fed with a sinusoidal voltage
2 of 4
Code No: RR12302 Set No. 1
V=20 sin100t.
i. Sketch the output waveform.
ii. Determine the DC output voltage assuming ideal diode behaviour.
iii. Repeat the calculations assuming the simplified diode (silicon) model.
Figure 4a
(b) Draw the circuit diagram of full wave rectifier having two diodes and explain
its operation. [8+8]
5. (a) Draw the circuit of transistor (p-n-p) in the CE configuration, sketch the
family of input and output characteristics and explain the shape of the curves
qualitatively.
(b) For the circuit in figure 5b shown find R. Neglect the reverse saturation current.
Assume silicon transistor is used.
[8+8]
Figure 5b
6. (a) Draw the circuit of a transformer coupled amplifier and explain its operations.
(b) Draw the circuit of a class B push-pull amplifier and derive expression for the
output power. [8+8]
7. (a) Explain the operation of an integrator using OP-AMPs.
(b) Distinguish between positive and negative feedbacks.
(c) List out the characteristics of OP-AMP. [6+4+6]
8. (a) Explain the principle of Half-adder. Draw various implementations of sum
and carry of Half-adder.
(b) Implement AND and OR gate using discrete components.
3 of 4
Code No: RR12302 Set No. 1
(c) How do you convert JK-flip-flop to T and D flip-flops. . [6+6+4]
⋆ ⋆ ⋆ ⋆ ⋆
4 of 4
Code No: RR12302 Set No. 2
I B.Tech Supplimentary Examinations, Aug/Sep 2007
ELECTRICAL AND ELECTRONICS ENGINEERING
(Bio-Technology)
Time: 3 hours Max Marks: 80
Answer any FIVE Questions
All Questions carry equal marks
⋆ ⋆ ⋆ ⋆ ⋆
1. (a) Derive the voltage current relations (between line and phase) values for a star
and delta connected systems.
(b) A 3-phase, 4 wire 208V system supplies power to a star connected load each
arm with impedance equal to (17.32 − j10) ohms (per phase) find the line
currents, power consumed, and the power factor of the load. [8+8]
2. (a) Explain the constructional details of a synchronous machine giving the reasons
for making two types of rotors.
(b) Explain auxiliary motor starting of synchronous motors. [6+10]
3. (a) Draw the V-I characteristics of Zener diode and explain.
(b) For the Zener voltage regulator shown in the figure 3b determine the range
of RL and IL that gives a stabilized voltage of 10 V. What should be wattage
rating of the diode?
Figure 3b
(c) Explain how Zener diode acts as voltage regulator. [4+8+4]
4. (a) The half wave rectifier shown in the figure 4a is fed with a sinusoidal voltage
V=20 sin100t.
i. Sketch the output waveform.
ii. Determine the DC output voltage assuming ideal diode behaviour.
iii. Repeat the calculations assuming the simplified diode (silicon) model.
1 of 2
Code No: RR12302 Set No. 2
Figure 4a
(b) Draw the circuit diagram of full wave rectifier having two diodes and explain
its operation. [8+8]
5. (a) Compare the merits and drawbacks of FET and BJT.
(b) Sketch the basic structure of an n-channel JFET.
(c) Define the pinch off voltage VP and sketch the depletion region before and
after pinch-off and explain the reason. [6+4+6]
6. (a) Give the advantages of negative feedback amplifier.
(b) Draw the circuit of a voltage shunt feedback amplifier and explain.
(c) When the negative feedback is applied to an amplifier of gain 100, the overall
gain falls to 50. Calculate
i. the feedback factor ’β’
ii. If the same feedback factor is maintained, find the value of amplifier gain
required if the overall gain is to be 75. [4+6+6]
7. (a) With the help of neat circuit diagram, explain the following applications of
OP-AMP
i. Multiplier
ii. differentiator
iii. Subtractor.
(b) Design a scaling adder circuit using OP-AMP, to give the output voltage
Vo = −(3V 1 +4V 2 +5V 3),where V1, V2 and V3 are the input voltages given to
the circuit. [10+6]
8. (a) Realize NAND gate using minimum number of NOR gates.
(b) Explain the principle of basic shift registers.
(c) Distinguish between asynchronous and synchronous counters.
(d) Distinguish between Ring and Twisted Ring counters. [4+4+4+4]
⋆ ⋆ ⋆ ⋆ ⋆
2 of 2
Code No: RR12302 Set No. 3
I B.Tech Supplimentary Examinations, Aug/Sep 2007
ELECTRICAL AND ELECTRONICS ENGINEERING
(Bio-Technology)
Time: 3 hours Max Marks: 80
Answer any FIVE Questions
All Questions carry equal marks
⋆ ⋆ ⋆ ⋆ ⋆
1. (a) Derive an equation for the total power consumed in a three ? phase circuit.
Will it depend on the type of load connected?
(b) Three identical impedances 106 53.10 ohm are connected in delta to a 3-phase,
240 volt balanced supply. Find the line currents and power consumed. [8+8]
2. (a) Give the various power stages of a 3-phase induction motor(the various stages
from the input to induction motor to output) and explain each stage.
(b) Explain principle of operation of three − phase induction motor. [8+8]
3. (a) Give the specifications of Zener diode.
(b) Explain the terms:
i. Space-charge region
ii. Transition region.
iii. Barrier potential.
iv. Donar impurities,
v. Acceptor impurities. [4+12]
4. (a) The half wave rectifier shown in the figure 4a is fed with a sinusoidal voltage
V=20 sin100t.
i. Sketch the output waveform.
ii. Determine the DC output voltage assuming ideal diode behaviour.
iii. Repeat the calculations assuming the simplified diode (silicon) model.
Figure 4a
(b) Draw the circuit diagram of full wave rectifier having two diodes and explain
its operation. [8+8]
1 of 3
Code No: RR12302 Set No. 3
5. (a) Draw the circuit of transistor (p-n-p) in the CE configuration, sketch the
family of input and output characteristics and explain the shape of the curves
qualitatively.
(b) For the circuit in figure 5b shown find R. Neglect the reverse saturation current.
Assume silicon transistor is used.
[8+8]
Figure 5b
6. (a) Draw the h-parameter small signal low-frequency BJT model and what are
the dimensions of each parameter.
(b) Draw the approximate h-parameter model for common collector configuration
and derive expressions for current gain, Input Resistance, voltage gain and
output resistance. [6+10]
7. (a) Draw the circuit diagram of Wien bridge oscillator using BJT. Show that the
gain of the amplifier must be at least 3 for the oscillations to occur.
(b) For the fixed-bias Ge transistor, n-p-n type, the junction voltages at satura-
tion and cutoff one in active region, may be assumed to zero. This circuit
operate properly over the temperature range -50 oC to 75 oC and to just start
malfunctioning at these extremes. The various circuit specifications are: VCC
= 4.5V, VBB = 3volts, hfe=40 at -50 oC, and hfe=60 at 75 oC, ICBO = 4
μA at 25 oC and doubles every 10 oC. Collector current is 10 μA. Design the
values of Rc1, R1 and R2. [8+8]
8. (a) Explain the following switching circuit in binary logic notation as shown in
the figure8a
Figure 8a
(b) Define a register. Construct a shift register using S-R flip-flops and explain
its operation.
(c) Convert the following numbers:
i. (101101. 101101)2 decimal number
2 of 3
Code No: RR12302 Set No. 3
ii. (5345)10 to binary number. [4+6+6]
⋆ ⋆ ⋆ ⋆ ⋆
3 of 3
Code No: RR12302 Set No. 4
I B.Tech Supplimentary Examinations, Aug/Sep 2007
ELECTRICAL AND ELECTRONICS ENGINEERING
(Bio-Technology)
Time: 3 hours Max Marks: 80
Answer any FIVE Questions
All Questions carry equal marks
⋆ ⋆ ⋆ ⋆ ⋆
1. (a) Define resistance.
(b) State and explain Ohms Law.
(c) Find out the equivalent resistance of the following circuit between the points
A and B (all values are in ohms) as shown in the figure 1c [2+4+4]
Figure 1c
(d) Find the impedance between ‘X’ and ‘Y’ points of the figure 1d shown. [6]
Figure 1d
2. (a) Discuss the classification of D.C generators with suitable diagrams, and give
the practical applications of each generator.
1 of 4
Code No: RR12302 Set No. 4
(b) A 10 kW shunt generator supplies load at a terminal voltage of 200 volts.
The shunt field resistance is 100 ohms and armature resistance is 0.1 ohm.
Calculate the e.m.f induced in the generator. [8+8]
3. (a) For the network shown in the figure 3(a)i determine the range of RL and IL
that will result in VRL being maintained at 10 V.
i. Determine the maximum Wattage rating of the diode.
Figure 3(a)i
ii. The reverse saturation current of the diode is 1 μA. Its peak inverse Volt-
age is 500V. Find ri, Vo that PIV is not exceeded. show in figure 3(a)ii &
figure 3(a)iii
Figure 3(a)ii
2 of 4
Code No: RR12302 Set No. 4
Figure 3(a)iii
4. (a) Draw the circuit diagram of half wave rectifier and explain its operation.
(b) A half wave rectifier is fed by 220 V, 50 Hz via a step down transformer of
turns ratio 11:1 find
i. the output DC and
ii. peak inverse voltage under no load condition. [8+8]
5. (a) Sketch a family of drain characteristics of JFET and explain the shape of the
curves qualitatively.
(b) Obtain transfer characteristic of JFET from its drain characteristics and ex-
plain the shape of curves qualitatively.
(c) How a JFET can be used as voltage variable resistor (VVR)? Explain.[4+6+6]
6. (a) Compare the three transistor amplifier configurations with related to AI , Av,
Ri and R0.
(b) For the circuit shown calculate AI , AV , Ri and R0 using approximate
h-parameter model. Assume hfe = 50, hie = 1100 , hoe = 25 μA/V, hre =
2.5 × 10−4 as shown in the figure 6b.
3 of 4
Code No: RR12302 Set No. 4
Figure 6b
7. (a) Explain the principle of operation of self-bias binary circuit.
(b) A FET phase shift oscillator has gm=500 μs, and rd = 30 k. The feedback
resistance is 100 k, and the capacitor value is 64.97 pF. Calculate the fre-
quency of oscillations and the value of RD. Draw the corresponding circuit
diagram.
[8+8]
8. (a) Realize Exclusive OR gate using minimum number of NAND gates.
(b) Realize SR flip-flop using NAND gates.
(c) Explain the principle of decade counter and realize it using JK-flip-flops.
(d) Realize exclusive OR gate using basic gates. [4+4+4+4]
⋆ ⋆ ⋆ ⋆ ⋆
4 of 4
ELECTRICAL AND ELECTRONICS ENGINEERING-SUPLY 2K6
Code No: RR12302 Set No. 1
I B.Tech Supplementary Examinations, Aug/Sep 2006
ELECTRICAL AND ELECTRONICS ENGINEERING
(Bio-Technology)
Time: 3 hours Max Marks: 80
Answer any FIVE Questions
All Questions carry equal marks
⋆ ⋆ ⋆ ⋆ ⋆
1. (a) Derive an expression for the total power consumed in a 3-phase, delta con-
nected load, connected to 3-phase balanced supply.
(b) Three equal impedances of (6+J8) ohm are connected in delta fashion across
400V, 3-phase balanced supply. Calculate the phase current, line current and
total power consumed by the load. [8+8]
2. (a) Define efficiency of a transformer? Obtain the condition for maximum effi-
ciency.
(b) A 25KVA, 2500 / 250V, 1-phase transformer has the following losses. Iron
loss = 960 watts, Full load copper loss = 1500 watts. Calculate at what load
maximum efficiency occurs, and the value of maximum efficiency at unity
power factor. [8+8]
3. (a) Determine Vo1 and Vo2 for the networks shown in the figure 1 and figure 2
below.
Figure 1:
(b) Explain the following terms.
i. Cut-in voltage
ii. Reverse saturation current.
iii. Forward bias
iv. Reverse bias. . [5+5+6]
4. (a) In a bridge rectifier, the transformer is connected to 220V, 60Hz mains and
the turns ratio of the step down transformer is 11:1. Load resistance is 800 .
Assuming the diode is ideal, find
1 of 3
Code No: RR12302 Set No. 1
Figure 2:
i. Idc
ii. Voltage across the load
iii. PIV
(b) Explain the following terms:
i. Ripple factor
ii. Peak Inverse voltage
iii. Efficiency
iv. TUF
v. Form factor
vi. Peak factor. [6+10]
5. (a) Define the following BJT switching times with suitable sketches..
i. Delay time,
ii. Turn-on Time
iii. Storage Time
iv. Fall time
v. turn-off time
(b) What are the bias compensation techniques? Explain the operation of one
among them.
(c) An n-p-n transistor with β = 50 is used in a CE circuit with VCC = 10V,
and RC = 2K. The bias is obtained by connecting a 100K resistance from
collector to base. Assume VBE=0V. Find the Quiescent point. [6+4+6]
6. (a) Define class A, B, AB, B and C operation of amplifiers.
(b) Draw the circuit diagram of a push-pull amplifier and explain how even har-
monics are eliminated.
(c) Derive the relation between gain with feed back and without feedback.[6+6+4]
7. (a) Draw the circuit diagram of wien bridge oscillator using BJT. Show that the
gain of the amplifier must be at least 3 for the oscillations to occur.
2 of 3
Code No: RR12302 Set No. 1
(b) For the fixed-bias Ge transistor, npn type, the junction voltages at saturation
and cutoff one in active region, may be assumed to zero. This circuit operate
properly over the temperature range -50oC to 75oC and to just start malfunc-
tioning at these extremes. The various circuit specifications are: VCC = 4.5v,
VBB = 3v, hFE=40 at -50oC, and hFE=60 at 75oC, ICBO = 4μA at 25oC and
doubles every 10oC. Collector current is 10μA. Design the values of Rc1, R1
and R2.. [8+8]
8. (a) Give the Boolean functions: F= xy + x′y′ +y′z
i. Implement with only OR and NOT gates.
ii. Implement with only AND and NOT gates.
(b) Explain the principle of master-slave JK flip-flop.
(c) Find the complement of given function and reduce it to a minimum number
of literals.(BC′+A′D) (AB′+CD′). [6+5+5]
⋆ ⋆ ⋆ ⋆ ⋆
3 of 3
Code No: RR12302 Set No. 2
I B.Tech Supplementary Examinations, Aug/Sep 2006
ELECTRICAL AND ELECTRONICS ENGINEERING
(Bio-Technology)
Time: 3 hours Max Marks: 80
Answer any FIVE Questions
All Questions carry equal marks
⋆ ⋆ ⋆ ⋆ ⋆
1. (a) State RMS value of a voltage waveform and find the RMS value and crest
factor of the waveform v(t) of figure.1 below
Figure 1:
(b) What is potential difference?
(c) An electric heater takes 3KWat 240 volts. Calculate the current and resistance
of the heating element. [10+2+4]
2. (a) Show that single phase induction motors are not self starting.
(b) Explain the construction and working principle of any type of 1-phase induc-
tion motor. [8+8]
3. (a) Draw the equivalent circuits of
i. ideal diode
ii. Simplified model
iii. piece wise linear model. Draw their characteristics.
(b) Derive the expression for diffusion capacitance in a diode. [10+6]
4. (a) The half wave rectifier shown in the figure:2 below is fed with a sinusoidal
voltage v=20sin100t.
i. Sketch the output waveform.
ii. Determine the d.c. output voltage assuming ideal diode behaviour.
iii. Repeat the calculations assuming the simplified diode (silicon) model.
(b) Draw the circuit diagram of full wave rectifier having two diodes and explain
its operation. [8+8]
5. (a) Draw the circuit of a transistor (n-p-n) in the CB configuration. Sketch the
input & output characteristics and explain the shape of the curves qualita-
tively.
1 of 3
Code No: RR12302 Set No. 2
Figure 2:
[8+8]
Figure 3:
(b) For the circuit in figure 3 shown below for n-p-n transistor, calculate the
collector and base currents. Assume hFE = 50. Explain Q point.
6. (a) Compare the three transistor amplifier configurations with related to AI , Av,
Ri and R0.
(b) For the circuit shown calculate AI , AV , Ri and R0, using approximate h-
parameter model. Assume hfe = 50, hie = 1100, hoe = 25 μA/V, hre = 2.5
× 10−4 as shown in the figure 4 below.
[6+10]
Figure 4:
2 of 3
Code No: RR12302 Set No. 2
7. (a) Explain the effect of temperature on
i. i/p bias current
ii. i/p off set current
iii. i/p offset voltage.
(b) Explain in brief the applications of OP AMP.. [8+8]
8. (a) State and prove D Morgau’s theorems.
(b) Realize NOR gate using minimum number of NAND gates.
(c) Find the 2’S complement of (46)10.. [5+5+6]
⋆ ⋆ ⋆ ⋆ ⋆
3 of 3
Code No: RR12302 Set No. 3
I B.Tech Supplementary Examinations, Aug/Sep 2006
ELECTRICAL AND ELECTRONICS ENGINEERING
(Bio-Technology)
Time: 3 hours Max Marks: 80
Answer any FIVE Questions
All Questions carry equal marks
⋆ ⋆ ⋆ ⋆ ⋆
1. (a) Define the terms
i. Average value
ii. R.M.S. value
iii. peak factor
iv. form factor.
(b) Determinate peak factor and form factor of the wave form shown in the figure
1 below.
Figure 1:
(c) Draw a rectangular waveform for the given specifications Vm = 10V, Time
period (T) =10m sec, Dutye cycle = 40%.. [5M+8M+3M]
2. (a) Give the constructional features of “CORE” and “Shell” types of transformers,
and give the advantages and disadvantages of each type.
(b) A 5 KVA, 2300 / 230V, 50 HZ transformer was tested for the iron loss with
normal excitation and copper losses at full load, and these were found to be
40 watts and 112 watts respectively. Calculate efficiency of the transformer at
i. full load.
ii. half full load.
Assume the power factor of the load as 0.8. [8+8]
3. (a) Determine Vo1 and Vo2 for the networks shown in the figure 2 and figure 3
below.
(b) Explain the following terms.
i. Cut-in voltage
ii. Reverse saturation current.
iii. Forward bias
iv. Reverse bias. . [5+5+6]
1 of 3
Code No: RR12302 Set No. 3
Figure 2:
Figure 3:
4. (a) The half wave rectifier shown in the figure:4 below is fed with a sinusoidal
voltage v=20sin100t.
i. Sketch the output waveform.
ii. Determine the d.c. output voltage assuming ideal diode behaviour.
iii. Repeat the calculations assuming the simplified diode (silicon) model.
Figure 4:
(b) Draw the circuit diagram of full wave rectifier having two diodes and explain
its operation. [8+8]
5. (a) Define the following BJT switching times with suitable sketches..
i. Delay time,
ii. Turn-on Time
2 of 3
Code No: RR12302 Set No. 3
iii. Storage Time
iv. Fall time
v. turn-off time
(b) What are the bias compensation techniques? Explain the operation of one
among them.
(c) An n-p-n transistor with β = 50 is used in a CE circuit with VCC = 10V,
and RC = 2K. The bias is obtained by connecting a 100K resistance from
collector to base. Assume VBE=0V. Find the Quiescent point. [6+4+6]
6. (a) Give the advantages of negative feedback amplifier.
(b) Draw the circuit of a voltage shunt feedback amplifier and explain.
(c) When the negative feedback is applied to an amplifier of gain 100, the overall
gain falls to 50. Calculate
i. the feedback factor ’β’
ii. If the same feedback factor is maintained, find the value of amplifier gain
required if the overall gain is to be 75. [4+6+6]
7. Define the following terms with reference to OP-AMPs:
(a) i/p bias current
(b) i/p offset current
(c) open loop gain
(d) i/p off set voltage
(e) o/p offset voltage
(f) CMRR
(g) PSSR
(h) Slew rate.. [16]
8. (a) Explain how a shift register is used as a Ring counter. Draw the O/P waveform
from each flip-flop of a 3-stage unit.
(b) Prove that if w′x + yz = 0, then wx + y′ (w′+z′) = wx + xz + x′z′ + w′y′z.
(c) Represent the given negative numbers in sign-magnetude, 1’S and 2’S com-
plement representation in 12-bit format.
i. -64
ii. -512.. [6+6+4]
⋆ ⋆ ⋆ ⋆ ⋆
3 of 3
Code No: RR12302 Set No. 4
I B.Tech Supplementary Examinations, Aug/Sep 2006
ELECTRICAL AND ELECTRONICS ENGINEERING
(Bio-Technology)
Time: 3 hours Max Marks: 80
Answer any FIVE Questions
All Questions carry equal marks
⋆ ⋆ ⋆ ⋆ ⋆
1. (a) Derive an equation for the total power consumed in a three phase circuit.
Will it depend on the type of load connected?
(b) Three identical impedances 106 53.10 ohm [10 (cos(53.1)0 + Jsin(53)0] are
connected in delta to a 3-phase, 240volt balanced supply. Find the line cur-
rents and power consumed. [8+8]
2. (a) Explain the constructional details of a synchronous machine giving the reasons
for making two types of rotors.
(b) Explain auxiliary motor starting of synchronous motors. [6+10]
3. (a) Determine the range of input voltage that maintains an output voltage of 10V
at the output for the regulator shown in the figure 1 below.
Figure 1:
(b) Explain the applications of Zener diode.
(c) Explain static and Dynamic Resistance of a diode. [4+8+4]
4. (a) Give the application of SCR, DIAC and TRIAC.
(b) For the network shown in the figure:2 below sketch V0 and determine Vdc if
i/p is a sine wave whose RMS value is 110v.
5. (a) Define different stability factors of biasing circuits using BJT.
(b) List out different transistor biasing methods and compare their merits and
demerits.
(c) Write short notes on
[8+8]
Figure 2:
i. Thermal runaway
ii. Early effect [6+6+4]
6. (a) Give the advantages of negative feedback amplifier.
(b) Draw the circuit of a voltage shunt feedback amplifier and explain.
(c) When the negative feedback is applied to an amplifier of gain 100, the overall
gain falls to 50. Calculate
i. the feedback factor ’β’
ii. If the same feedback factor is maintained, find the value of amplifier gain
required if the overall gain is to be 75. [4+6+6]
7. (a) List out the characteristics of OP-AMP.
(b) Explain about the concept of ‘virtual Ground’ in OP AMPs.
(c) Draw the circuit diagram of emitter coupled differential amplifier and obtain
its d.c analysis.. [6+4+6]
8. (a) Explain with a block diagram the major blocks of a digital computer.
(b) Implement the following with either NAND or NOR gates. Use only 4 gates
only the normal inputs are available.
F = w′xz + w′yz + x′yz′ + wxy′z.
(c) With a circuit diagram, explain Counter type A-to-D converter.. [4+6+6]
. [8+8]
⋆ ⋆ ⋆ ⋆ ⋆
2 of 2
I B.Tech Supplementary Examinations, Aug/Sep 2006
ELECTRICAL AND ELECTRONICS ENGINEERING
(Bio-Technology)
Time: 3 hours Max Marks: 80
Answer any FIVE Questions
All Questions carry equal marks
⋆ ⋆ ⋆ ⋆ ⋆
1. (a) Derive an expression for the total power consumed in a 3-phase, delta con-
nected load, connected to 3-phase balanced supply.
(b) Three equal impedances of (6+J8) ohm are connected in delta fashion across
400V, 3-phase balanced supply. Calculate the phase current, line current and
total power consumed by the load. [8+8]
2. (a) Define efficiency of a transformer? Obtain the condition for maximum effi-
ciency.
(b) A 25KVA, 2500 / 250V, 1-phase transformer has the following losses. Iron
loss = 960 watts, Full load copper loss = 1500 watts. Calculate at what load
maximum efficiency occurs, and the value of maximum efficiency at unity
power factor. [8+8]
3. (a) Determine Vo1 and Vo2 for the networks shown in the figure 1 and figure 2
below.
Figure 1:
(b) Explain the following terms.
i. Cut-in voltage
ii. Reverse saturation current.
iii. Forward bias
iv. Reverse bias. . [5+5+6]
4. (a) In a bridge rectifier, the transformer is connected to 220V, 60Hz mains and
the turns ratio of the step down transformer is 11:1. Load resistance is 800 .
Assuming the diode is ideal, find
1 of 3
Code No: RR12302 Set No. 1
Figure 2:
i. Idc
ii. Voltage across the load
iii. PIV
(b) Explain the following terms:
i. Ripple factor
ii. Peak Inverse voltage
iii. Efficiency
iv. TUF
v. Form factor
vi. Peak factor. [6+10]
5. (a) Define the following BJT switching times with suitable sketches..
i. Delay time,
ii. Turn-on Time
iii. Storage Time
iv. Fall time
v. turn-off time
(b) What are the bias compensation techniques? Explain the operation of one
among them.
(c) An n-p-n transistor with β = 50 is used in a CE circuit with VCC = 10V,
and RC = 2K. The bias is obtained by connecting a 100K resistance from
collector to base. Assume VBE=0V. Find the Quiescent point. [6+4+6]
6. (a) Define class A, B, AB, B and C operation of amplifiers.
(b) Draw the circuit diagram of a push-pull amplifier and explain how even har-
monics are eliminated.
(c) Derive the relation between gain with feed back and without feedback.[6+6+4]
7. (a) Draw the circuit diagram of wien bridge oscillator using BJT. Show that the
gain of the amplifier must be at least 3 for the oscillations to occur.
2 of 3
Code No: RR12302 Set No. 1
(b) For the fixed-bias Ge transistor, npn type, the junction voltages at saturation
and cutoff one in active region, may be assumed to zero. This circuit operate
properly over the temperature range -50oC to 75oC and to just start malfunc-
tioning at these extremes. The various circuit specifications are: VCC = 4.5v,
VBB = 3v, hFE=40 at -50oC, and hFE=60 at 75oC, ICBO = 4μA at 25oC and
doubles every 10oC. Collector current is 10μA. Design the values of Rc1, R1
and R2.. [8+8]
8. (a) Give the Boolean functions: F= xy + x′y′ +y′z
i. Implement with only OR and NOT gates.
ii. Implement with only AND and NOT gates.
(b) Explain the principle of master-slave JK flip-flop.
(c) Find the complement of given function and reduce it to a minimum number
of literals.(BC′+A′D) (AB′+CD′). [6+5+5]
⋆ ⋆ ⋆ ⋆ ⋆
3 of 3
Code No: RR12302 Set No. 2
I B.Tech Supplementary Examinations, Aug/Sep 2006
ELECTRICAL AND ELECTRONICS ENGINEERING
(Bio-Technology)
Time: 3 hours Max Marks: 80
Answer any FIVE Questions
All Questions carry equal marks
⋆ ⋆ ⋆ ⋆ ⋆
1. (a) State RMS value of a voltage waveform and find the RMS value and crest
factor of the waveform v(t) of figure.1 below
Figure 1:
(b) What is potential difference?
(c) An electric heater takes 3KWat 240 volts. Calculate the current and resistance
of the heating element. [10+2+4]
2. (a) Show that single phase induction motors are not self starting.
(b) Explain the construction and working principle of any type of 1-phase induc-
tion motor. [8+8]
3. (a) Draw the equivalent circuits of
i. ideal diode
ii. Simplified model
iii. piece wise linear model. Draw their characteristics.
(b) Derive the expression for diffusion capacitance in a diode. [10+6]
4. (a) The half wave rectifier shown in the figure:2 below is fed with a sinusoidal
voltage v=20sin100t.
i. Sketch the output waveform.
ii. Determine the d.c. output voltage assuming ideal diode behaviour.
iii. Repeat the calculations assuming the simplified diode (silicon) model.
(b) Draw the circuit diagram of full wave rectifier having two diodes and explain
its operation. [8+8]
5. (a) Draw the circuit of a transistor (n-p-n) in the CB configuration. Sketch the
input & output characteristics and explain the shape of the curves qualita-
tively.
1 of 3
Code No: RR12302 Set No. 2
Figure 2:
[8+8]
Figure 3:
(b) For the circuit in figure 3 shown below for n-p-n transistor, calculate the
collector and base currents. Assume hFE = 50. Explain Q point.
6. (a) Compare the three transistor amplifier configurations with related to AI , Av,
Ri and R0.
(b) For the circuit shown calculate AI , AV , Ri and R0, using approximate h-
parameter model. Assume hfe = 50, hie = 1100, hoe = 25 μA/V, hre = 2.5
× 10−4 as shown in the figure 4 below.
[6+10]
Figure 4:
2 of 3
Code No: RR12302 Set No. 2
7. (a) Explain the effect of temperature on
i. i/p bias current
ii. i/p off set current
iii. i/p offset voltage.
(b) Explain in brief the applications of OP AMP.. [8+8]
8. (a) State and prove D Morgau’s theorems.
(b) Realize NOR gate using minimum number of NAND gates.
(c) Find the 2’S complement of (46)10.. [5+5+6]
⋆ ⋆ ⋆ ⋆ ⋆
3 of 3
Code No: RR12302 Set No. 3
I B.Tech Supplementary Examinations, Aug/Sep 2006
ELECTRICAL AND ELECTRONICS ENGINEERING
(Bio-Technology)
Time: 3 hours Max Marks: 80
Answer any FIVE Questions
All Questions carry equal marks
⋆ ⋆ ⋆ ⋆ ⋆
1. (a) Define the terms
i. Average value
ii. R.M.S. value
iii. peak factor
iv. form factor.
(b) Determinate peak factor and form factor of the wave form shown in the figure
1 below.
Figure 1:
(c) Draw a rectangular waveform for the given specifications Vm = 10V, Time
period (T) =10m sec, Dutye cycle = 40%.. [5M+8M+3M]
2. (a) Give the constructional features of “CORE” and “Shell” types of transformers,
and give the advantages and disadvantages of each type.
(b) A 5 KVA, 2300 / 230V, 50 HZ transformer was tested for the iron loss with
normal excitation and copper losses at full load, and these were found to be
40 watts and 112 watts respectively. Calculate efficiency of the transformer at
i. full load.
ii. half full load.
Assume the power factor of the load as 0.8. [8+8]
3. (a) Determine Vo1 and Vo2 for the networks shown in the figure 2 and figure 3
below.
(b) Explain the following terms.
i. Cut-in voltage
ii. Reverse saturation current.
iii. Forward bias
iv. Reverse bias. . [5+5+6]
1 of 3
Code No: RR12302 Set No. 3
Figure 2:
Figure 3:
4. (a) The half wave rectifier shown in the figure:4 below is fed with a sinusoidal
voltage v=20sin100t.
i. Sketch the output waveform.
ii. Determine the d.c. output voltage assuming ideal diode behaviour.
iii. Repeat the calculations assuming the simplified diode (silicon) model.
Figure 4:
(b) Draw the circuit diagram of full wave rectifier having two diodes and explain
its operation. [8+8]
5. (a) Define the following BJT switching times with suitable sketches..
i. Delay time,
ii. Turn-on Time
2 of 3
Code No: RR12302 Set No. 3
iii. Storage Time
iv. Fall time
v. turn-off time
(b) What are the bias compensation techniques? Explain the operation of one
among them.
(c) An n-p-n transistor with β = 50 is used in a CE circuit with VCC = 10V,
and RC = 2K. The bias is obtained by connecting a 100K resistance from
collector to base. Assume VBE=0V. Find the Quiescent point. [6+4+6]
6. (a) Give the advantages of negative feedback amplifier.
(b) Draw the circuit of a voltage shunt feedback amplifier and explain.
(c) When the negative feedback is applied to an amplifier of gain 100, the overall
gain falls to 50. Calculate
i. the feedback factor ’β’
ii. If the same feedback factor is maintained, find the value of amplifier gain
required if the overall gain is to be 75. [4+6+6]
7. Define the following terms with reference to OP-AMPs:
(a) i/p bias current
(b) i/p offset current
(c) open loop gain
(d) i/p off set voltage
(e) o/p offset voltage
(f) CMRR
(g) PSSR
(h) Slew rate.. [16]
8. (a) Explain how a shift register is used as a Ring counter. Draw the O/P waveform
from each flip-flop of a 3-stage unit.
(b) Prove that if w′x + yz = 0, then wx + y′ (w′+z′) = wx + xz + x′z′ + w′y′z.
(c) Represent the given negative numbers in sign-magnetude, 1’S and 2’S com-
plement representation in 12-bit format.
i. -64
ii. -512.. [6+6+4]
⋆ ⋆ ⋆ ⋆ ⋆
3 of 3
Code No: RR12302 Set No. 4
I B.Tech Supplementary Examinations, Aug/Sep 2006
ELECTRICAL AND ELECTRONICS ENGINEERING
(Bio-Technology)
Time: 3 hours Max Marks: 80
Answer any FIVE Questions
All Questions carry equal marks
⋆ ⋆ ⋆ ⋆ ⋆
1. (a) Derive an equation for the total power consumed in a three phase circuit.
Will it depend on the type of load connected?
(b) Three identical impedances 106 53.10 ohm [10 (cos(53.1)0 + Jsin(53)0] are
connected in delta to a 3-phase, 240volt balanced supply. Find the line cur-
rents and power consumed. [8+8]
2. (a) Explain the constructional details of a synchronous machine giving the reasons
for making two types of rotors.
(b) Explain auxiliary motor starting of synchronous motors. [6+10]
3. (a) Determine the range of input voltage that maintains an output voltage of 10V
at the output for the regulator shown in the figure 1 below.
Figure 1:
(b) Explain the applications of Zener diode.
(c) Explain static and Dynamic Resistance of a diode. [4+8+4]
4. (a) Give the application of SCR, DIAC and TRIAC.
(b) For the network shown in the figure:2 below sketch V0 and determine Vdc if
i/p is a sine wave whose RMS value is 110v.
5. (a) Define different stability factors of biasing circuits using BJT.
(b) List out different transistor biasing methods and compare their merits and
demerits.
(c) Write short notes on
[8+8]
Figure 2:
i. Thermal runaway
ii. Early effect [6+6+4]
6. (a) Give the advantages of negative feedback amplifier.
(b) Draw the circuit of a voltage shunt feedback amplifier and explain.
(c) When the negative feedback is applied to an amplifier of gain 100, the overall
gain falls to 50. Calculate
i. the feedback factor ’β’
ii. If the same feedback factor is maintained, find the value of amplifier gain
required if the overall gain is to be 75. [4+6+6]
7. (a) List out the characteristics of OP-AMP.
(b) Explain about the concept of ‘virtual Ground’ in OP AMPs.
(c) Draw the circuit diagram of emitter coupled differential amplifier and obtain
its d.c analysis.. [6+4+6]
8. (a) Explain with a block diagram the major blocks of a digital computer.
(b) Implement the following with either NAND or NOR gates. Use only 4 gates
only the normal inputs are available.
F = w′xz + w′yz + x′yz′ + wxy′z.
(c) With a circuit diagram, explain Counter type A-to-D converter.. [4+6+6]
. [8+8]
⋆ ⋆ ⋆ ⋆ ⋆
2 of 2
ELECTRICAL AND ELECTRONICS ENGINEERING-SUPLY2K5
Code No: RR12302 Set No. 1
I B.Tech Supplementary Examinations, November/December 2005
ELECTRICAL AND ELECTRONICS ENGINEERING
(Bio-Technology)
Time: 3 hours Max Marks: 80
Answer any FIVE Questions
All Questions carry equal marks
⋆ ⋆ ⋆ ⋆ ⋆
1. (a) Determine the effective resistance between the nodes A and B in the circuit
shown in the figure 1 below (all values are in ohms).
Figure 1:
(b) Find the Vc and IL from the circuit shown in Figure 2under steady state
conditions. [10+6]
Figure 2:
2. (a) Why is the core of the transformer laminated?
(b) What are the various losses in a transformer? And how do these losses vary?
(c) A single phase 50HZ transformer has 100 turns on the primary and 400 turns
on the secondary. The cross sectional area of the core is 250 cm2. The primary
winding is connected to 230 volts. Determine
i. E.M.F induced in the secondary winding.
ii. The maximum value of the flux density in the core. [4+8+4]
3. (a) Explain how an n-type semiconductor is formed. Name different donor impu-
rities used.
(b) i. Find the conductivity of intrinsic silicon at 3000K.
1 of 3
Code No: RR12302 Set No. 1
ii. If donor impurity is added to the extent of 1 impurity atom in 108 silicon
atoms, find the conductivity. It is given that at 3000K,
ni = 1.5 × 1010/Cm3, μp = 500Cm2/v − s, μn = 1300Cm2/V − S..
[4+4+8]
4. (a) Describe the basic structure of DIAC. Draw its volt-ampere characteristics
and explain.
(b) Define and explain the following terms of SCR
i. Turn-on-time
ii. Turn-off-time
(c) Draw the two transistor representation of SCR and explain. [8+4+4]
5. (a) Compare and contrast of FET and BJT.
(b) Give the constructional features of JFET and explain its operation with the
help of the drain characteristics.
(c) From the drain characteristics derive mutual characteristic and explain the
shape of the curve qualitatively. [6+6+4]
6. (a) Compare the three transistor amplifier configurations with related to AI , Av,
Ri and R0.
(b) For the circuit shown calculate AI , AV , Ri and R0, using approximate h-
parameter model. Assume hfe = 50, hie = 1100, hoe = 25 μA/V, hre = 2.5
× 10−4 as shown in the figure 3 below.
[6+10]
Figure 3:
7. (a) Explain the operation of monostable multi vibrator with relevant waveforms.
(b) How Frequency stability can be improved in the oscillators? Explain.
(c) For phase shift oscillator, the feedback network uses R=6k and C=1500pF.
The transistorized amplifier used, has a collector resistance of 18k. Calcu-
late the frequency of oscillations and minimum value of hfe of the transistor.
[6+4+6]
2 of 3
Code No: RR12302 Set No. 1
8. (a) Realize Full-adder using logic gates.
(b) Explain the principle of operation of D-to-A converter.
(c) Simplify the following functions
i. A′BC′ + A′C′D + A′B′D′ + AC + BCD′
ii. A′B′D′ + A′CD + A′BC. [4 +4+8]
⋆ ⋆ ⋆ ⋆ ⋆
3 of 3
Code No: RR12302 Set No. 2
I B.Tech Supplementary Examinations, November/December 2005
ELECTRICAL AND ELECTRONICS ENGINEERING
(Bio-Technology)
Time: 3 hours Max Marks: 80
Answer any FIVE Questions
All Questions carry equal marks
⋆ ⋆ ⋆ ⋆ ⋆
1. (a) Explain the principle of operation of single-phase energy meter.
(b) A single phase energy meter is used to measure the energy consumption of
factory. The factory load is 100KW and is in continuous use for 6000 hrs
per annum. If the meter constant is 600 revolutions per KWhr, how many
revolutions the disc of the energy meter makes. [6+10]
2. (a) Discuss the torque − armature current characteristics of various types of d.c
motors and give the practical applications of each type of motor.
(b) Discuss classification of d.c motors with suitable diagrams. [8+8]
3. (a) i. Find the resistivity of intrinsic silicon at 3000K. It is given the ni at 3000K
in silicon is 1.5×1010/Cm3 andμp = 500Cm2/V −S, μn = 1300Cm2/V −
S.
ii. If an acceptor impurity is added to the extent of 1 imputrity atom in
2 × 108 silicon atoms, find its resistivity.
iii. If a donor impurity is added to the extent of 1 impurity atom in 5 × 107
silicon atoms, find its resistivity.
(b) Prove that the concentration of free electron in an intrinsic semiconductor is
given by n = Nce−(Ec−Ef )/KT [12+4]
4. (a) Describe the basic structure of DIAC. Draw its volt-ampere characteristics
and explain.
(b) Define and explain the following terms of SCR
i. Turn-on-time
ii. Turn-off-time
(c) Draw the two transistor representation of SCR and explain. [8+4+4]
5. (a) Draw a family of drain characteristics and mutual characteristics of an n-
channel FET and explain the shape of the curves qualitatively.
(b) Define FET parameters and derive the relationship between them. [8+8]
6. (a) Compare the three transistor amplifier configurations with related to AI , Av,
Ri and R0.
(b) For the circuit shown calculate AI , AV , Ri and R0, using approximate h-
parameter model. Assume hfe = 50, hie = 1100, hoe = 25 μA/V, hre = 2.5
× 10−4 as shown in the figure 1 below.
1 of 2
Code No: RR12302 Set No. 2
[6+10]
Figure 1:
7. (a) Draw the circuit diagram of wien bridge oscillator using BJT. Show that the
gain of the amplifier must be at least 3 for the oscillations to occur.
(b) For the fixed-bias Ge transistor, npn type, the junction voltages at saturation
and cutoff one in active region, may be assumed to zero. This circuit operate
properly over the temperature range -50oC to 75oC and to just start malfunc-
tioning at these extremes. The various circuit specifications are: VCC = 4.5v,
VBB = 3v, hFE=40 at -50oC, and hFE=60 at 75oC, ICBO = 4μA at 25oC and
doubles every 10oC. Collector current is 10μA. Design the values of Rc1, R1
and R2.. [8+8]
8. (a) Distinguish between positive and negative logic.
(b) Represent the decimal number 8620 in binary.
(c) How do you convert an RS flip-flop into a T-flipflop?
(d) Distinguish between Truth table and excitation table.. [4+4+4+4]
⋆ ⋆ ⋆ ⋆ ⋆
2 of 2
Code No: RR12302 Set No. 3
I B.Tech Supplementary Examinations, November/December 2005
ELECTRICAL AND ELECTRONICS ENGINEERING
(Bio-Technology)
Time: 3 hours Max Marks: 80
Answer any FIVE Questions
All Questions carry equal marks
⋆ ⋆ ⋆ ⋆ ⋆
1. (a) Determine the effective resistance between the nodes A and B in the circuit
shown in the figure 1 below (all values are in ohms).
Figure 1:
(b) Find the Vc and IL from the circuit shown in Figure 2under steady state
conditions. [10+6]
Figure 2:
2. (a) Show that single phase induction motors are not self starting.
(b) Explain the construction and working principle of any type of 1-phase induc-
tion motor. [8+8]
3. (a) Give the electronics configurations of Silicon and Germanium.
(b) What is the difference between intrinsic and extrinsic semi-conductors.
(c) Draw energy band diagrams of
i. Insulator
ii. Semiconductor and
iii. Metal, and hence explain the difference in their conductivities. [4+4+8]
1 of 3
Code No: RR12302 Set No. 3
4. (a) The half wave rectifier shown in the figure:3 below is fed with a sinusoidal
voltage v=20sin100t.
i. Sketch the output waveform.
ii. Determine the d.c. output voltage assuming ideal diode behaviour.
iii. Repeat the calculations assuming the simplified diode (silicon) model.
Figure 3:
(b) Draw the circuit diagram of full wave rectifier having two diodes and explain
its operation. [8+8]
5. (a) Define different stability factors of biasing circuits using BJT.
(b) List out different transistor biasing methods and compare their merits and
demerits.
(c) Write short notes on
i. Thermal runaway
ii. Early effect [6+6+4]
6. (a) Draw the circuit of a transformer coupled amplifier and explain its operations.
(b) Draw the circuit of a class B push-pull amplifier and derive expression for the
output power. [8+8]
7. (a) Draw the circuit diagram of wien bridge oscillator using BJT. Show that the
gain of the amplifier must be at least 3 for the oscillations to occur.
(b) For the fixed-bias Ge transistor, npn type, the junction voltages at saturation
and cutoff one in active region, may be assumed to zero. This circuit operate
properly over the temperature range -50oC to 75oC and to just start malfunc-
tioning at these extremes. The various circuit specifications are: VCC = 4.5v,
VBB = 3v, hFE=40 at -50oC, and hFE=60 at 75oC, ICBO = 4μA at 25oC and
doubles every 10oC. Collector current is 10μA. Design the values of Rc1, R1
and R2.. [8+8]
8. (a) Explain how a shift register is used as a Ring counter. Draw the O/P waveform
from each flip-flop of a 3-stage unit.
(b) Prove that if w′x + yz = 0, then wx + y′ (w′+z′) = wx + xz + x′z′ + w′y′z.
(c) Represent the given negative numbers in sign-magnetude, 1’S and 2’S com-
plement representation in 12-bit format.
2 of 3
Code No: RR12302 Set No. 3
i. -64
ii. -512.. [6+6+4]
⋆ ⋆ ⋆ ⋆ ⋆
3 of 3
Code No: RR12302 Set No. 4
I B.Tech Supplementary Examinations, November/December 2005
ELECTRICAL AND ELECTRONICS ENGINEERING
(Bio-Technology)
Time: 3 hours Max Marks: 80
Answer any FIVE Questions
All Questions carry equal marks
⋆ ⋆ ⋆ ⋆ ⋆
1. (a) Derive an expression for the total power consumed in a 3-phase, delta con-
nected load, connected to 3-phase balanced supply.
(b) Three equal impedances of (6+J8) ohm are connected in delta fashion across
400V, 3-phase balanced supply. Calculate the phase current, line current and
total power consumed by the load. [8+8]
2. (a) Discuss the classification of d.c generators with suitable diagrams, and give
the practical applications of each generator.
(b) A 10Kw shunt generator supplies load at a terminal voltage of 200 volts.
The shunt field resistance is 100 ohms and armature resistance is 0.1 ohm.
Calculate the e.m.f induced in the generator.. [8+8]
3. (a) Explain how an n-type semiconductor is formed. Name different donor impu-
rities used.
(b) i. Find the conductivity of intrinsic silicon at 3000K.
ii. If donor impurity is added to the extent of 1 impurity atom in 108 silicon
atoms, find the conductivity. It is given that at 3000K,
ni = 1.5 × 1010/Cm3, μp = 500Cm2/v − s, μn = 1300Cm2/V − S..
[4+4+8]
4. (a) A sinusoidal voltage of peak value 40V and frequency 50Hz is applied to HWR
using PN diode. The total load resistor is 800. Neglecting cut in voltage and
using idealized characteristic for the diode with Rf=8 and Rr=α calculate
i. Peak d.c and RMS values of load current
ii. d.c. and a.c. output power
iii. Rectifier efficiency
iv. Ripple factor.
(b) Derive the formulas used in the above problem. [8+8]
5. (a) Sketch a family of drain and mutual characteristics and explain the shape of
the curves qualitatively for a JFET.
(b) For a source self-bias circuit if ID = 0.8 mA, IDSS = 1.65 mA and VP = -2V
find VGS. [8+8]
6. (a) Define class A, B, AB, B and C operation of amplifiers.
(b) Draw the circuit diagram of a push-pull amplifier and explain how even har-
monics are eliminated.
(c) Derive the relation between gain with feed back and without feedback.[6+6+4]
7. (a) With the help of neat circuit diagram, explain the following applications of
OP-AMP.
i. Multiplier
ii. differentiator
iii. Subtractor.
(b) Design a scaling adder circuit using OP-AMP, to give the output voltage
Vo = −(3V 1 +4V 2 +5V 3),where V1, V2 and V3 are the input voltages given to
the circuit.. [10+6]
8. (a) Explain how a shift register is used as a Ring counter. Draw the O/P waveform
from each flip-flop of a 3-stage unit.
(b) Prove that if w′x + yz = 0, then wx + y′ (w′+z′) = wx + xz + x′z′ + w′y′z.
(c) Represent the given negative numbers in sign-magnetude, 1’S and 2’S com-
plement representation in 12-bit format.
i. -64
ii. -512.. [6+6+4]
I B.Tech Supplementary Examinations, November/December 2005
ELECTRICAL AND ELECTRONICS ENGINEERING
(Bio-Technology)
Time: 3 hours Max Marks: 80
Answer any FIVE Questions
All Questions carry equal marks
⋆ ⋆ ⋆ ⋆ ⋆
1. (a) Determine the effective resistance between the nodes A and B in the circuit
shown in the figure 1 below (all values are in ohms).
Figure 1:
(b) Find the Vc and IL from the circuit shown in Figure 2under steady state
conditions. [10+6]
Figure 2:
2. (a) Why is the core of the transformer laminated?
(b) What are the various losses in a transformer? And how do these losses vary?
(c) A single phase 50HZ transformer has 100 turns on the primary and 400 turns
on the secondary. The cross sectional area of the core is 250 cm2. The primary
winding is connected to 230 volts. Determine
i. E.M.F induced in the secondary winding.
ii. The maximum value of the flux density in the core. [4+8+4]
3. (a) Explain how an n-type semiconductor is formed. Name different donor impu-
rities used.
(b) i. Find the conductivity of intrinsic silicon at 3000K.
1 of 3
Code No: RR12302 Set No. 1
ii. If donor impurity is added to the extent of 1 impurity atom in 108 silicon
atoms, find the conductivity. It is given that at 3000K,
ni = 1.5 × 1010/Cm3, μp = 500Cm2/v − s, μn = 1300Cm2/V − S..
[4+4+8]
4. (a) Describe the basic structure of DIAC. Draw its volt-ampere characteristics
and explain.
(b) Define and explain the following terms of SCR
i. Turn-on-time
ii. Turn-off-time
(c) Draw the two transistor representation of SCR and explain. [8+4+4]
5. (a) Compare and contrast of FET and BJT.
(b) Give the constructional features of JFET and explain its operation with the
help of the drain characteristics.
(c) From the drain characteristics derive mutual characteristic and explain the
shape of the curve qualitatively. [6+6+4]
6. (a) Compare the three transistor amplifier configurations with related to AI , Av,
Ri and R0.
(b) For the circuit shown calculate AI , AV , Ri and R0, using approximate h-
parameter model. Assume hfe = 50, hie = 1100, hoe = 25 μA/V, hre = 2.5
× 10−4 as shown in the figure 3 below.
[6+10]
Figure 3:
7. (a) Explain the operation of monostable multi vibrator with relevant waveforms.
(b) How Frequency stability can be improved in the oscillators? Explain.
(c) For phase shift oscillator, the feedback network uses R=6k and C=1500pF.
The transistorized amplifier used, has a collector resistance of 18k. Calcu-
late the frequency of oscillations and minimum value of hfe of the transistor.
[6+4+6]
2 of 3
Code No: RR12302 Set No. 1
8. (a) Realize Full-adder using logic gates.
(b) Explain the principle of operation of D-to-A converter.
(c) Simplify the following functions
i. A′BC′ + A′C′D + A′B′D′ + AC + BCD′
ii. A′B′D′ + A′CD + A′BC. [4 +4+8]
⋆ ⋆ ⋆ ⋆ ⋆
3 of 3
Code No: RR12302 Set No. 2
I B.Tech Supplementary Examinations, November/December 2005
ELECTRICAL AND ELECTRONICS ENGINEERING
(Bio-Technology)
Time: 3 hours Max Marks: 80
Answer any FIVE Questions
All Questions carry equal marks
⋆ ⋆ ⋆ ⋆ ⋆
1. (a) Explain the principle of operation of single-phase energy meter.
(b) A single phase energy meter is used to measure the energy consumption of
factory. The factory load is 100KW and is in continuous use for 6000 hrs
per annum. If the meter constant is 600 revolutions per KWhr, how many
revolutions the disc of the energy meter makes. [6+10]
2. (a) Discuss the torque − armature current characteristics of various types of d.c
motors and give the practical applications of each type of motor.
(b) Discuss classification of d.c motors with suitable diagrams. [8+8]
3. (a) i. Find the resistivity of intrinsic silicon at 3000K. It is given the ni at 3000K
in silicon is 1.5×1010/Cm3 andμp = 500Cm2/V −S, μn = 1300Cm2/V −
S.
ii. If an acceptor impurity is added to the extent of 1 imputrity atom in
2 × 108 silicon atoms, find its resistivity.
iii. If a donor impurity is added to the extent of 1 impurity atom in 5 × 107
silicon atoms, find its resistivity.
(b) Prove that the concentration of free electron in an intrinsic semiconductor is
given by n = Nce−(Ec−Ef )/KT [12+4]
4. (a) Describe the basic structure of DIAC. Draw its volt-ampere characteristics
and explain.
(b) Define and explain the following terms of SCR
i. Turn-on-time
ii. Turn-off-time
(c) Draw the two transistor representation of SCR and explain. [8+4+4]
5. (a) Draw a family of drain characteristics and mutual characteristics of an n-
channel FET and explain the shape of the curves qualitatively.
(b) Define FET parameters and derive the relationship between them. [8+8]
6. (a) Compare the three transistor amplifier configurations with related to AI , Av,
Ri and R0.
(b) For the circuit shown calculate AI , AV , Ri and R0, using approximate h-
parameter model. Assume hfe = 50, hie = 1100, hoe = 25 μA/V, hre = 2.5
× 10−4 as shown in the figure 1 below.
1 of 2
Code No: RR12302 Set No. 2
[6+10]
Figure 1:
7. (a) Draw the circuit diagram of wien bridge oscillator using BJT. Show that the
gain of the amplifier must be at least 3 for the oscillations to occur.
(b) For the fixed-bias Ge transistor, npn type, the junction voltages at saturation
and cutoff one in active region, may be assumed to zero. This circuit operate
properly over the temperature range -50oC to 75oC and to just start malfunc-
tioning at these extremes. The various circuit specifications are: VCC = 4.5v,
VBB = 3v, hFE=40 at -50oC, and hFE=60 at 75oC, ICBO = 4μA at 25oC and
doubles every 10oC. Collector current is 10μA. Design the values of Rc1, R1
and R2.. [8+8]
8. (a) Distinguish between positive and negative logic.
(b) Represent the decimal number 8620 in binary.
(c) How do you convert an RS flip-flop into a T-flipflop?
(d) Distinguish between Truth table and excitation table.. [4+4+4+4]
⋆ ⋆ ⋆ ⋆ ⋆
2 of 2
Code No: RR12302 Set No. 3
I B.Tech Supplementary Examinations, November/December 2005
ELECTRICAL AND ELECTRONICS ENGINEERING
(Bio-Technology)
Time: 3 hours Max Marks: 80
Answer any FIVE Questions
All Questions carry equal marks
⋆ ⋆ ⋆ ⋆ ⋆
1. (a) Determine the effective resistance between the nodes A and B in the circuit
shown in the figure 1 below (all values are in ohms).
Figure 1:
(b) Find the Vc and IL from the circuit shown in Figure 2under steady state
conditions. [10+6]
Figure 2:
2. (a) Show that single phase induction motors are not self starting.
(b) Explain the construction and working principle of any type of 1-phase induc-
tion motor. [8+8]
3. (a) Give the electronics configurations of Silicon and Germanium.
(b) What is the difference between intrinsic and extrinsic semi-conductors.
(c) Draw energy band diagrams of
i. Insulator
ii. Semiconductor and
iii. Metal, and hence explain the difference in their conductivities. [4+4+8]
1 of 3
Code No: RR12302 Set No. 3
4. (a) The half wave rectifier shown in the figure:3 below is fed with a sinusoidal
voltage v=20sin100t.
i. Sketch the output waveform.
ii. Determine the d.c. output voltage assuming ideal diode behaviour.
iii. Repeat the calculations assuming the simplified diode (silicon) model.
Figure 3:
(b) Draw the circuit diagram of full wave rectifier having two diodes and explain
its operation. [8+8]
5. (a) Define different stability factors of biasing circuits using BJT.
(b) List out different transistor biasing methods and compare their merits and
demerits.
(c) Write short notes on
i. Thermal runaway
ii. Early effect [6+6+4]
6. (a) Draw the circuit of a transformer coupled amplifier and explain its operations.
(b) Draw the circuit of a class B push-pull amplifier and derive expression for the
output power. [8+8]
7. (a) Draw the circuit diagram of wien bridge oscillator using BJT. Show that the
gain of the amplifier must be at least 3 for the oscillations to occur.
(b) For the fixed-bias Ge transistor, npn type, the junction voltages at saturation
and cutoff one in active region, may be assumed to zero. This circuit operate
properly over the temperature range -50oC to 75oC and to just start malfunc-
tioning at these extremes. The various circuit specifications are: VCC = 4.5v,
VBB = 3v, hFE=40 at -50oC, and hFE=60 at 75oC, ICBO = 4μA at 25oC and
doubles every 10oC. Collector current is 10μA. Design the values of Rc1, R1
and R2.. [8+8]
8. (a) Explain how a shift register is used as a Ring counter. Draw the O/P waveform
from each flip-flop of a 3-stage unit.
(b) Prove that if w′x + yz = 0, then wx + y′ (w′+z′) = wx + xz + x′z′ + w′y′z.
(c) Represent the given negative numbers in sign-magnetude, 1’S and 2’S com-
plement representation in 12-bit format.
2 of 3
Code No: RR12302 Set No. 3
i. -64
ii. -512.. [6+6+4]
⋆ ⋆ ⋆ ⋆ ⋆
3 of 3
Code No: RR12302 Set No. 4
I B.Tech Supplementary Examinations, November/December 2005
ELECTRICAL AND ELECTRONICS ENGINEERING
(Bio-Technology)
Time: 3 hours Max Marks: 80
Answer any FIVE Questions
All Questions carry equal marks
⋆ ⋆ ⋆ ⋆ ⋆
1. (a) Derive an expression for the total power consumed in a 3-phase, delta con-
nected load, connected to 3-phase balanced supply.
(b) Three equal impedances of (6+J8) ohm are connected in delta fashion across
400V, 3-phase balanced supply. Calculate the phase current, line current and
total power consumed by the load. [8+8]
2. (a) Discuss the classification of d.c generators with suitable diagrams, and give
the practical applications of each generator.
(b) A 10Kw shunt generator supplies load at a terminal voltage of 200 volts.
The shunt field resistance is 100 ohms and armature resistance is 0.1 ohm.
Calculate the e.m.f induced in the generator.. [8+8]
3. (a) Explain how an n-type semiconductor is formed. Name different donor impu-
rities used.
(b) i. Find the conductivity of intrinsic silicon at 3000K.
ii. If donor impurity is added to the extent of 1 impurity atom in 108 silicon
atoms, find the conductivity. It is given that at 3000K,
ni = 1.5 × 1010/Cm3, μp = 500Cm2/v − s, μn = 1300Cm2/V − S..
[4+4+8]
4. (a) A sinusoidal voltage of peak value 40V and frequency 50Hz is applied to HWR
using PN diode. The total load resistor is 800. Neglecting cut in voltage and
using idealized characteristic for the diode with Rf=8 and Rr=α calculate
i. Peak d.c and RMS values of load current
ii. d.c. and a.c. output power
iii. Rectifier efficiency
iv. Ripple factor.
(b) Derive the formulas used in the above problem. [8+8]
5. (a) Sketch a family of drain and mutual characteristics and explain the shape of
the curves qualitatively for a JFET.
(b) For a source self-bias circuit if ID = 0.8 mA, IDSS = 1.65 mA and VP = -2V
find VGS. [8+8]
6. (a) Define class A, B, AB, B and C operation of amplifiers.
(b) Draw the circuit diagram of a push-pull amplifier and explain how even har-
monics are eliminated.
(c) Derive the relation between gain with feed back and without feedback.[6+6+4]
7. (a) With the help of neat circuit diagram, explain the following applications of
OP-AMP.
i. Multiplier
ii. differentiator
iii. Subtractor.
(b) Design a scaling adder circuit using OP-AMP, to give the output voltage
Vo = −(3V 1 +4V 2 +5V 3),where V1, V2 and V3 are the input voltages given to
the circuit.. [10+6]
8. (a) Explain how a shift register is used as a Ring counter. Draw the O/P waveform
from each flip-flop of a 3-stage unit.
(b) Prove that if w′x + yz = 0, then wx + y′ (w′+z′) = wx + xz + x′z′ + w′y′z.
(c) Represent the given negative numbers in sign-magnetude, 1’S and 2’S com-
plement representation in 12-bit format.
i. -64
ii. -512.. [6+6+4]
ELECTRICAL AND ELECTRONICS ENGINEERING -JUN 2K5REG
Code No: RR12302 Set No.1
I B.Tech. Regular Examinations, June -2005
ELECTRICAL AND ELECTRONICS ENGINEERING
(Bio-Technology)
Time: 3 hours Max Marks: 80
Answer any FIVE Questions
All Questions carry equal marks
? ? ? ? ?
1. (a) State RMS value of a voltage waveform and ¯nd the RMS value and crest
factor of the waveform v(t) of ¯gure.1 below
Figure 1:
(b) What is potential di®erence?
(c) An electric heater takes 3KW at 240 volts. Calculate the current and resistance
of the heating element.
2. (a) Why is the core of the transformer laminated?
(b) What are the various losses in a transformer? And how do these losses vary?
(c) A single phase 50HZ transformer has 100 turns on the primary and 400 turns
on the secondary. The cross sectional area of the core is 250 cm2: The primary
winding is connected to 230 volts. Determine
i. E.M.F induced in the secondary winding.
ii. The maximum value of the °ux density in the core.
3. (a) Shown that for circuit show in the ¯gure 2 below, the output voltage is 5V
when either V1 or V2 or both is 5V. Assume the ideal behaviour of the diode.
(b) Determine Vo and IDfor the networks shown in the ¯gure 3.
4. (a) A full wave bridge recti¯er is fed with 220v, 50Hz, through a step-down trans-
former of turns ratio 11:1. Assuming ideal diode ¯nd the
i. d.c. output voltage
ii. peak inverse voltage
iii. Recti¯er e±ciency. The load resistance is 100.
(b) What is ripple factor? Show that the ripple factor for full wave recti¯er is
0.482.
5. (a) Compare the merits and drawbacks of FET and BJT.
1 of 2
Code No: RR12302 Set No.1
Figure 2:
Figure 3:
2 of 2
Code No: RR12302 Set No.1
(b) Sketch the basic structure of an n-channel JFET.
(c) De¯ne the pinch o® voltage VP and sketch the depletion region before and
after pinch-o® and explain the reason.
6. (a) Draw the circuit diagram of an emitter follower circuit and its h-parameter
model.
(b) For the given component values Rs = 1K, RL = 3K and for the given h-
parameters hfe = 100, hie = 2K, hre = 2.5 x 10¡4, hoe = 10¹A/V. Calculate
AI , RI , Avs, Avs and R0.
7. De¯ne the following terms with reference to OP-AMPs:
(a) i/p bias current
(b) i/p o®set current
(c) open loop gain
(d) i/p o® set voltage
(e) o/p o®set voltage
(f) CMRR
(g) PSSR
(h) Slew rate.
8. (a) Realize NAND gate using minimum number of NOR gates.
(b) Explain the principle of basic shift registers.
(c) Distinguish between asynchronous and synchronous counters.
(d) Distinguish between Ring and Twisted Ring counters.
? ? ? ? ?
3 of 2
Code No: RR12302 Set No.2
I B.Tech. Regular Examinations, June -2005
ELECTRICAL AND ELECTRONICS ENGINEERING
(Bio-Technology)
Time: 3 hours Max Marks: 80
Answer any FIVE Questions
All Questions carry equal marks
? ? ? ? ?
1. (a) Derive the voltage current relations (between line and phase) values for a star
¡ and ¡ delta connected systems.
(b) A 3-phase, 4 wire 208V system supplies power to a star connected load each
arm with impedance equal to (17.32 ¡ J10) ohms (per phase) ¯nd the line
currents, power consumed, and the power factor of the load.
2. (a) Why is the core of the transformer laminated?
(b) What are the various losses in a transformer? And how do these losses vary?
(c) A single phase 50HZ transformer has 100 turns on the primary and 400 turns
on the secondary. The cross sectional area of the core is 250 cm2: The primary
winding is connected to 230 volts. Determine
i. E.M.F induced in the secondary winding.
ii. The maximum value of the °ux density in the core.
3. (a) Determine the range of input voltage that maintains an output voltage of 10V
at the output for the regulator shown in the ¯gure 4 below.
Figure 4:
(b) Explain the applications of Zener diode.
(c) Explain static and Dynamic Resistance of a diode.
4. (a) Draw the circuit diagram of half wave recti¯er and explain its operation.
(b) A half wave recti¯er is fed by 220V, 50Hz via a step down transformer of turns
ratio 11:1 ¯nd
i. the output d.c. and
1 of 2
Code No: RR12302 Set No.2
ii. peak inverse voltage under no load condition.
5. (a) Compare the merits and drawbacks of FET and BJT.
(b) Sketch the basic structure of an n-channel JFET.
(c) De¯ne the pinch o® voltage VP and sketch the depletion region before and
after pinch-o® and explain the reason.
6. (a) Compare the di®erences between voltage ampli¯ers and power ampli¯ers.
(b) Show that the maximum theoretical e±ciency of class B push-pull ampli¯ers
is 78.5%.
(c) Draw the circuit of a transformer coupled power ampli¯er and explain its
operations with help of load-line analysis.
7. (a) Explain the e®ect of temperature on
i. i/p bias current
ii. i/p o® set current
iii. i/p o®set voltage.
(b) Explain in brief the applications of OP AMP.
8. (a) Convert the following numbers:
i. (1431)10 to base 2.
ii. (53:1575)10 to base 2.
(b) Implement AB+C0D0 = F with three NAND gates. Draw the logic circuit.
(c) Prove that the NAND Gate is a universal gate.
? ? ? ? ?
2 of 2
Code No: RR12302 Set No.3
I B.Tech. Regular Examinations, June -2005
ELECTRICAL AND ELECTRONICS ENGINEERING
(Bio-Technology)
Time: 3 hours Max Marks: 80
Answer any FIVE Questions
All Questions carry equal marks
? ? ? ? ?
1. Consider a general A.C circuit in which the current leads the applied voltage by
an angle Á. Write the equation for the voltage and current and hence derive the
equation for the power. Also plot the voltage, current and power wave forms.
2. (a) Discuss the classi¯cation of d.c generators with suitable diagrams, and give
the practical applications of each generator.
(b) A 10Kw shunt generator supplies load at a terminal voltage of 200 volts.
The shunt ¯eld resistance is 100 ohms and armature resistance is 0.1 ohm.
Calculate the e.m.f induced in the generator.
3. (a) Explain the Law of junction for p-n diode.
(b) Explain Avalanche and Zener break downs and compare.
(c) Derive Diode current equation.
4. (a) What are the principle feature of a bridge recti¯er. Explain its operation with
neat circuit diagram.
(b) Describe the characteristics of a triac.
5. (a) Sketch the input and output characteristics of CB con¯guration for an n-p-n
transistor, Explain the shape of the curves qualitatively.
(b) For the circuit in ¯gure:5 shown below if ® = 0.98 VBE = 0.7V ¯nd R1 in the
circuit for an emitter current of IE = -2mA. Neglect the reverse saturation
current.
Figure 5:
6. (a) Draw the h-parameter small signal low-frequency BJT model and what are
the dimensions of each parameter.
1 of 2
Code No: RR12302 Set No.3
(b) Draw the approximate h-parameter model for common collector con¯guration
and derive expressions for current gain, Input Resistance voltage gain and
output resistance.
7. (a) Find the resistance R and hfe for the transistor to provide a resonating fre-
quency of 5kHz of a transistorized phase shift oscillator. The biasing resis-
tances are 25k and 47k. The load resistance is 10. The capacitor in the
tank circuit is 1000pF which hie of the transistor is 2k.
(b) Explain the role of commutating capacitors in multivibrator circuits.
(c) Design an Astable multivibrator circuit with 50% duty cycle and f=2KHz,
VCC=10v, VBE(Sat) = 0.6v, VCE(Sat) = 0.3v. Using NPN Si transistors.
8. (a) Realize Exclusive-OR gate using minimum number of NAND gates.
(b) Realize SR °ip-°op using NAND gates.
(c) Explain the principle of decade counter and realize it using JK-°ip°ops.
(d) Realize exclusive ¡OR gate using basic gates.
? ? ? ? ?
2 of 2
Code No: RR12302 Set No.4
I B.Tech. Regular Examinations, June -2005
ELECTRICAL AND ELECTRONICS ENGINEERING
(Bio-Technology)
Time: 3 hours Max Marks: 80
Answer any FIVE Questions
All Questions carry equal marks
? ? ? ? ?
1. (a) Derive an expression for the total power in a 3-phase circuit in terms of line
voltages and line currents. Show that the power is same whether the load is
delta connected or star connected.
(b) A 3-phase balanced star-connected load consists of 100 ohms resistance con-
nected across a 220V, 3-phase supply. Determine the line currents and total
power consumed.
2. (a) Does the induction motor have any similarities with the transformer? Com-
pare the similarities and di®erences between them.
(b) A 20h.p, 400V, 50HZ, 3-phase induction motor has an e±ciency of 80% and
working at 0.7p.f. The motor is connected to 400 volts, 3-phase supply calcu-
late the current drawn by the motor from the mains.
3. (a) Give the speci¯cations of Zener diode.
(b) Explain the terms:
i. Space-charge region
ii. Transition region.
iii. Barrier potential.
iv. Donar impurities,
v. Acceptor impurities.
4. (a) Draw the circuit diagram of half wave recti¯er and explain its operation.
(b) A half wave recti¯er is fed by 220V, 50Hz via a step down transformer of turns
ratio 11:1 ¯nd
i. the output d.c. and
ii. peak inverse voltage under no load condition.
5. (a) Draw the circuit of a transistor (n-p-n) in the CB con¯guration. Sketch the
input & output characteristics and explain the shape of the curves qualita-
tively.
(b) For the circuit in ¯gure 6 shown below for n-p-n transistor, calculate the
collector and base currents. Assume hFE = 50. Explain Q point.
6. (a) Draw the circuit of a current shunt feedback ampli¯er and explain.
(b) An ampli¯er has a gain of 10,000 without feedback. The gain is reduced to 50
with negative feedback. Find the feedback factor.
Figure 6:
(c) Explain the principle of operations of Tuned ampli¯ers.
7. (a) Explain the working principle of Colpitt's oscillator and derive the formula
for the O/P signal frequency. What is the basic di®erence between RC phase
shift oscillator and Hartley oscillator?
(b) Explain the principle of operation of self-bias binary circuit.
8. (a) Explain with a block diagram the major blocks of a digital computer.
(b) Implement the following with either NAND or NOR gates. Use only 4 gates
only the normal inputs are available.
F = w0xz + w0yz + x0yz0 + wxy0z.
(c) With a circuit diagram, explain Counter type A-to-D converter.
? ? ? ? ?
ELECTRICAL AND ELECTRONICS ENGINEERING-SUPPLY 2K4
Code No: RR-12302
I B.Tech. Supplementary Examinations, Nov/Dec-2004
ELECTRICAL AND ELECTRONICS ENGINEERING
(Bio-Technology)
Time: 3 hours Max Marks: 80
Answer any FIVE Questions
All Questions carry equal marks
- - -
1.a) With a neat sketch explain the construction and principle of operation of
dynamometer type watt meter.
b) Two 40w tube lights are ON for a period of six hours a day. Calculate the total
energy consumed by them in a month?
2.a) Discuss the torque – armature current characteristics of various types of d.c
motors and give the practical applications of each type of motor.
b) Discuss classification of d.c motors with suitable diagrams.
3.a) Give the electronics configurations of Silicon and Germanium.
b) What is the difference between intrinsic and extrinsic semi-conductors.
c) Draw energy band diagrams of (i) Insulator (ii) Semiconductor and
(iii) Metal, and hence explain the difference in their conductivities.
4.a) Draw the circuit diagram of half wave rectifier and explain its operation.
b) A half wave rectifier is fed by 220V, 50Hz via a step down transformer of turns
ratio 11:1 find i) the output d.c. and ii) peak inverse voltage under no load
condition.
5.a) Draw the emitter characteristic of UJT and explain the shape of the curve
qualitatively. Mention different regions of operations.
b) Draw the circuit of a relaxation oscillator and explain its operations. Mention it’s
applications.
6.a) Draw the circuit of a transformer coupled amplifier and explain its operations.
b) Draw the circuit of a class B push-pull amplifier and derive expression for the
output power.
7.a) Discuss and explain the basic circuit of an LC oscillator and derive the condition
for the oscillations.
b) Compare various multivibrators.
8.a) Show that the dual of the exclusive-OR in equal to its complement.
b) Design a synchronous counter with the binary. Sequence: 0, 1, 2, 3 and repeat use
RS flipflops.
c) Show that a positive-logic AND gate is a negative-logic OR gate.
*$*$*$*
Set No.
1
Code No: RR-12302
I B.Tech. Supplementary Examinations, Nov/Dec-2004
ELECTRICAL AND ELECTRONICS ENGINEERING
(Bio -Technology)
Time: 3 hours Max Marks: 80
Answer any FIVE Questions
All Questions carry equal marks
- - -
1.a) Derive the voltage current relations (between line and phase) values for a
star – and – delta connected systems.
b) A 3-phase, 4 wire 208V system supplies power to a star connected load each arm
with impedance equal to (17.32 – J10) ohms (per phase) find the line currents,
power consumed, and the power factor of the load.
2.a) Describe the construction of a 1-phase transformer and principle of operation.
b) Write about 3-phase transformer connections.
3.a) Explain how a P-type semiconductor is formed. What are the different impurities
used for this process.
b) Derive the expression for intrinsic conductivity.
c) Explain about charge densities in a semiconductor.
4.a) What do you mean by regulation and explain how a full wave rectifier is used for
it.
b) Compare center tapped transformer and ordinary transformer. What is the
difference in their construction?
c) Mention the applications of Rectifiers in detail.
5.a) Compare and contrast of FET and BJT.
b) Give the constructional features of JFET and explain its operation with the help of
the drain characteristics.
c) From the drain characteristics derive mutual characteristic and explain the shape
of the curve qualitatively.
6.a) Draw the circuit of a current shunt feedback amplifier and explain.
b) An amplifier has a gain of 10,000 without feedback. The gain is reduced to 50
with negative feedback. Find the feedback factor.
c) Explain the principle of operations of Tuned amplifiers.
7.a) Distinguish between symmetrical and asymmetrical triggering methods in
multivibrators.
b) Explain the operation of bistable multivibrator circuit with base and collector
waveforms.
Contd…2
Set No.
2
Code No: RR-12302 -2- Set No-2
8.a) Explain the working principle of a 4-bit binary up and down counter with its truth
table.
b) Show that a negative-logic AND gate is a positive-logic OR gate.
c) Distinguish between edge-triggering and level triggering.
*$*$*$*
Code No: RR-12302
I B.Tech. Supplementary Examinations, Nov/Dec-2004
ELECTRICAL AND ELECTRONICS ENGINEERING
(Bio-Technology)
Time: 3 hours Max Marks: 80
Answer any FIVE Questions
All Questions carry equal marks
- - -
1.a) Derive an equation for the total power consumed in a three – phase circuit.
Will it depend on the type of load connected?
b) Three identical impedances 10Ð53.10 ohm [10 (cos(53.1)0 + Jsin(53)0] are
connected in delta to a 3-phase, 240volt balanced supply. Find the line currents
and power consumed.
2.a) Discuss the construction of various types of 3-phase induction motor.
b) Explain the terms (i) Synchronous speed (ii) slip
c) A 4-pole 3-phase induction motor operates from 440V, 3-phase 50 HZ supply.
and runs at a speed of 1440 r.p.m What are the values of synchronous speed,
slip speed and percentage slip.
3.a) Explain the Law of junction for p-n diode.
b) Explain Avalanche and Zener break downs and compare.
c) Derive Diode current equation.
4.a) Explain the specifications and applications of DIAC, TRIAC and SCR.
b) Compare and contrast the construction and characteristic features of DIAC and
TRIAC.
5.a) Sketch a family of drain characteristics of JFET and explain the shape of the
curves qualitatively.
b) Obtain transfer characteristic of JFET from its drain characteristics and explain
the shape of curves qualitatively.
c) How a JFET can be used as voltage variable resistor (VVR)? Explain.
6. Derive the expression for input and output resistances of voltage series and
current shunt feedback amplifiers.
7.a) Explain the working principle of Colpitt’s oscillator and derive the formula for the
O/P signal frequency.
b) Explain the operation of one-shot circuit with relevant waveforms.
8.a) Verify the truth table for the 3-input exclusive OR gate. List a1l 8 combinations
of x, y, and z. Evaluate A = x Å y Å z.
b) Show the logic diagram of a clocked D flipflop with AND and OR gates, explain
it.
c) Explain the principle of clocked RS-flipflop with its logic diagram.
*$*$*$*
Set No.
3
Code No: RR-12302
I B.Tech. Supplementary Examinations, Nov/Dec-2004
ELECTRICAL AND ELECTRONICS ENGINEERING
(Bio Technology)
Time: 3 hours Max Marks: 80
Answer any FIVE Questions
All Questions carry equal marks
- - -
1.a) Explain the production of 3-phase voltages.
b) Derive relation between phase and line values of voltages and currents of star
and delta connected systems.
c) A 3-phase star connected load draws a current of 10Ð300 per phase from a
3- phase, 440V, supply. Calculate the line current.
2.a) Give the various power stages of a 3-phase induction motor the various stages
from the input to induction motor to output) and explain each stage.
b) Explain principle of operation of three – phase induction motor.
3.a) Draw the V-I characteristics of Zener diode and explain.
b) For the Zener voltage regulator shown below determine range of RL and IL that
gives a stabilized voltage of 10V. What should be wattage rating of the diode.
c) Explain how Zener diode acts and voltage regulator.
4.a) Explain with neat circuit diagram how SCR can be used as HWR.
b) Explain how SCR can be used as a switch.
c) Explain the turn on mechanism of SCR.
5.a) Explain qualitatively the three consequences of base-width modulation.
b) Sketch a family of CE input, output characteristics for the given npn BJT and
explain shape of the curves qualitatively.
c) How a transistor circuit acts as a switch. Explain with suitable example.
6.a) Compare the four feedback amplifier configurations with reference to the gain
Bandwidth, Rif and Rof.
b) Derive the expression for Avf, Rif, Rof and Ro’f of an emitter folower circuit.
7.a) Explain the principle of operation of self-bias binary circuit.
b) A FET phase shift oscillator has gm=500ms, and rd = 30kW. The feedback
resistance is 100kW, and the capacitor value is 64.97pF. Calculate the frequency
of oscillations and the value of RD. Draw the corresponding circuit diagram.
8.a) Construct a 4-bit left shift register using D-flipflops and explain its operation with
reference to clock.
b) Draw the logic diagrams for D-flipflop and T-flipflop and explain their working
with truth table.
c) Explain the working of decade counter and realize it using T-flipflops.
*$*$*$*
I B.Tech. Supplementary Examinations, Nov/Dec-2004
ELECTRICAL AND ELECTRONICS ENGINEERING
(Bio-Technology)
Time: 3 hours Max Marks: 80
Answer any FIVE Questions
All Questions carry equal marks
- - -
1.a) With a neat sketch explain the construction and principle of operation of
dynamometer type watt meter.
b) Two 40w tube lights are ON for a period of six hours a day. Calculate the total
energy consumed by them in a month?
2.a) Discuss the torque – armature current characteristics of various types of d.c
motors and give the practical applications of each type of motor.
b) Discuss classification of d.c motors with suitable diagrams.
3.a) Give the electronics configurations of Silicon and Germanium.
b) What is the difference between intrinsic and extrinsic semi-conductors.
c) Draw energy band diagrams of (i) Insulator (ii) Semiconductor and
(iii) Metal, and hence explain the difference in their conductivities.
4.a) Draw the circuit diagram of half wave rectifier and explain its operation.
b) A half wave rectifier is fed by 220V, 50Hz via a step down transformer of turns
ratio 11:1 find i) the output d.c. and ii) peak inverse voltage under no load
condition.
5.a) Draw the emitter characteristic of UJT and explain the shape of the curve
qualitatively. Mention different regions of operations.
b) Draw the circuit of a relaxation oscillator and explain its operations. Mention it’s
applications.
6.a) Draw the circuit of a transformer coupled amplifier and explain its operations.
b) Draw the circuit of a class B push-pull amplifier and derive expression for the
output power.
7.a) Discuss and explain the basic circuit of an LC oscillator and derive the condition
for the oscillations.
b) Compare various multivibrators.
8.a) Show that the dual of the exclusive-OR in equal to its complement.
b) Design a synchronous counter with the binary. Sequence: 0, 1, 2, 3 and repeat use
RS flipflops.
c) Show that a positive-logic AND gate is a negative-logic OR gate.
*$*$*$*
Set No.
1
Code No: RR-12302
I B.Tech. Supplementary Examinations, Nov/Dec-2004
ELECTRICAL AND ELECTRONICS ENGINEERING
(Bio -Technology)
Time: 3 hours Max Marks: 80
Answer any FIVE Questions
All Questions carry equal marks
- - -
1.a) Derive the voltage current relations (between line and phase) values for a
star – and – delta connected systems.
b) A 3-phase, 4 wire 208V system supplies power to a star connected load each arm
with impedance equal to (17.32 – J10) ohms (per phase) find the line currents,
power consumed, and the power factor of the load.
2.a) Describe the construction of a 1-phase transformer and principle of operation.
b) Write about 3-phase transformer connections.
3.a) Explain how a P-type semiconductor is formed. What are the different impurities
used for this process.
b) Derive the expression for intrinsic conductivity.
c) Explain about charge densities in a semiconductor.
4.a) What do you mean by regulation and explain how a full wave rectifier is used for
it.
b) Compare center tapped transformer and ordinary transformer. What is the
difference in their construction?
c) Mention the applications of Rectifiers in detail.
5.a) Compare and contrast of FET and BJT.
b) Give the constructional features of JFET and explain its operation with the help of
the drain characteristics.
c) From the drain characteristics derive mutual characteristic and explain the shape
of the curve qualitatively.
6.a) Draw the circuit of a current shunt feedback amplifier and explain.
b) An amplifier has a gain of 10,000 without feedback. The gain is reduced to 50
with negative feedback. Find the feedback factor.
c) Explain the principle of operations of Tuned amplifiers.
7.a) Distinguish between symmetrical and asymmetrical triggering methods in
multivibrators.
b) Explain the operation of bistable multivibrator circuit with base and collector
waveforms.
Contd…2
Set No.
2
Code No: RR-12302 -2- Set No-2
8.a) Explain the working principle of a 4-bit binary up and down counter with its truth
table.
b) Show that a negative-logic AND gate is a positive-logic OR gate.
c) Distinguish between edge-triggering and level triggering.
*$*$*$*
Code No: RR-12302
I B.Tech. Supplementary Examinations, Nov/Dec-2004
ELECTRICAL AND ELECTRONICS ENGINEERING
(Bio-Technology)
Time: 3 hours Max Marks: 80
Answer any FIVE Questions
All Questions carry equal marks
- - -
1.a) Derive an equation for the total power consumed in a three – phase circuit.
Will it depend on the type of load connected?
b) Three identical impedances 10Ð53.10 ohm [10 (cos(53.1)0 + Jsin(53)0] are
connected in delta to a 3-phase, 240volt balanced supply. Find the line currents
and power consumed.
2.a) Discuss the construction of various types of 3-phase induction motor.
b) Explain the terms (i) Synchronous speed (ii) slip
c) A 4-pole 3-phase induction motor operates from 440V, 3-phase 50 HZ supply.
and runs at a speed of 1440 r.p.m What are the values of synchronous speed,
slip speed and percentage slip.
3.a) Explain the Law of junction for p-n diode.
b) Explain Avalanche and Zener break downs and compare.
c) Derive Diode current equation.
4.a) Explain the specifications and applications of DIAC, TRIAC and SCR.
b) Compare and contrast the construction and characteristic features of DIAC and
TRIAC.
5.a) Sketch a family of drain characteristics of JFET and explain the shape of the
curves qualitatively.
b) Obtain transfer characteristic of JFET from its drain characteristics and explain
the shape of curves qualitatively.
c) How a JFET can be used as voltage variable resistor (VVR)? Explain.
6. Derive the expression for input and output resistances of voltage series and
current shunt feedback amplifiers.
7.a) Explain the working principle of Colpitt’s oscillator and derive the formula for the
O/P signal frequency.
b) Explain the operation of one-shot circuit with relevant waveforms.
8.a) Verify the truth table for the 3-input exclusive OR gate. List a1l 8 combinations
of x, y, and z. Evaluate A = x Å y Å z.
b) Show the logic diagram of a clocked D flipflop with AND and OR gates, explain
it.
c) Explain the principle of clocked RS-flipflop with its logic diagram.
*$*$*$*
Set No.
3
Code No: RR-12302
I B.Tech. Supplementary Examinations, Nov/Dec-2004
ELECTRICAL AND ELECTRONICS ENGINEERING
(Bio Technology)
Time: 3 hours Max Marks: 80
Answer any FIVE Questions
All Questions carry equal marks
- - -
1.a) Explain the production of 3-phase voltages.
b) Derive relation between phase and line values of voltages and currents of star
and delta connected systems.
c) A 3-phase star connected load draws a current of 10Ð300 per phase from a
3- phase, 440V, supply. Calculate the line current.
2.a) Give the various power stages of a 3-phase induction motor the various stages
from the input to induction motor to output) and explain each stage.
b) Explain principle of operation of three – phase induction motor.
3.a) Draw the V-I characteristics of Zener diode and explain.
b) For the Zener voltage regulator shown below determine range of RL and IL that
gives a stabilized voltage of 10V. What should be wattage rating of the diode.
c) Explain how Zener diode acts and voltage regulator.
4.a) Explain with neat circuit diagram how SCR can be used as HWR.
b) Explain how SCR can be used as a switch.
c) Explain the turn on mechanism of SCR.
5.a) Explain qualitatively the three consequences of base-width modulation.
b) Sketch a family of CE input, output characteristics for the given npn BJT and
explain shape of the curves qualitatively.
c) How a transistor circuit acts as a switch. Explain with suitable example.
6.a) Compare the four feedback amplifier configurations with reference to the gain
Bandwidth, Rif and Rof.
b) Derive the expression for Avf, Rif, Rof and Ro’f of an emitter folower circuit.
7.a) Explain the principle of operation of self-bias binary circuit.
b) A FET phase shift oscillator has gm=500ms, and rd = 30kW. The feedback
resistance is 100kW, and the capacitor value is 64.97pF. Calculate the frequency
of oscillations and the value of RD. Draw the corresponding circuit diagram.
8.a) Construct a 4-bit left shift register using D-flipflops and explain its operation with
reference to clock.
b) Draw the logic diagrams for D-flipflop and T-flipflop and explain their working
with truth table.
c) Explain the working of decade counter and realize it using T-flipflops.
*$*$*$*
ELECTRICAL AND ELECTRONICS ENGINEERING-REG 2K4
Code No:RR12302
I B.Tech Regular Examination, May/June 2004
ELECTRICAL AND ELECTRONICS ENGINEERING
(Bio Technology)
Time: 3 hours. Max.Marks:80
Answer any FIVE questions.
All questions carry equal marks.
- - -
1. a) Write down the expression for the instantaneous power, and hence derive the
equation for the average power.
b) A series R-L-C circuit consists of 100 ohms resistor and an inductor of 0.318
Henry and a capacitor of unknown value. This circuit is supplied by 230V, 50 HZ
supply and draws a current of 2.3 ohms, and the current is in phase with the
supply voltage. Find i) the value of the capacitance, and the power supplied by the
source.
2.a) Derive the equation for the voltage generated in a d.c generator.
b) A 2 pole d.c generator has 200 conductors on its armature. It is driven by a
prime mover at a constant speed of 600 r.p.m. If the flux per pole is 0.1 wb,
calculate the emf generated.
3.a) Prove that the Fermi level for p-type semiconductor is given by
. ln
= +
A
V
F V N
N
E E KT
b) In a p-type semiconductor, if the concentration of acceptor atoms is increased by a
factor 10, find the shift in the position of Fermi level. Assume KT=0.03ev.
4.a) A HWR has a load of 3.5KW. If the diode resistance and secondary coil
resistance together have a resistance of 800W and the input voltage has a signal
voltage of peak value 240v, Calculate
i) Peak, average and RMS value of current flowing.
ii) dc power output
iii) AC power input
iv) Efficiency of the rectifier.
b) Compare Half wave, Center tapped full wave and Bridge rectifiers.
5.a) Draw a self bias circuit using n-p-n transistor and derive expression for stability
factor S'.
b) A transistor with b = 100 is to be used in a CE configuration with collector-tobase
bias. If RC = 1KW and Va = 10V. Assume VBE = 0 and it is required to have
a quiescent collector-to-emitter voltage is 4V. Find the value of RB and the
stability factors S and S'.
Contd….2
Set No:
1
Code No:RR12302 -2- Set No:1
6. a) Compare the differences between voltage amplifiers and power amplifiers.
b) Show that the maximum theoretical efficiency of class B push-pull amplifiers is
78.5%.
c) Draw the circuit of a transformer coupled power amplifier and explain its
operations with help of load-line analysis.
7.a) Draw the internal diagram of OP-AMP. Explain the function of each block.
b) What do you understand about the term “Virtual ground”? Give the circuit
diagram for differentiate circuit using OP-AMP and prove that a triangular
waveform with frequency 5KHz is converted into rectangular waveform of the
same frequency.
8. a) Realize Exclusive-OR gate using minimum number of NAND gates.
b) Realize SR flip-flop using NAND gates.
c) Explain the principle of decade counter and realize it using JK-flipflops.
d) Realize exclusive –OR gate using basic gates.
***********
Code No:RR12302
I B.Tech Regular Examination, May/June 2004
ELECTRICAL AND ELECTRONICS ENGINEERING
(Bio Technology)
Time: 3 hours. Max.Marks:80
Answer any FIVE questions.
All questions carry equal marks.
- - -
1. Consider a general A.C circuit in which the current leads the applied voltage
by an angle f . Write the equation for the voltage and current and hence derive the
equation for the power. Also plot the voltage, current and power wave forms.
2.a) Explain the process of voltage build up in a self-excited d.c machine.
b) List out the various conditions to be satisfied for voltage build up process in a
self-excited machine, and write down remedies if the conditions fail.
3.a) Draw the V-I characteristics of p-n diode and explain.
b) (i) What is the current in the diode shown in the fig.
(ii) Calculate the load voltage load power, diode power and total power in the
above circuit.
c) Explain how p-n junction diode act as a rectifier.
4.a) In a bridge rectifier, the transformer is connected to 220V, 60Hz mains and the
turns ratio of the step down transformer is 11:1. Load resistance is 800 W.
Assuming the diode is ideal, find
i) Idc
ii) Voltage across the load
iii) PIV
b) Explain the following terms:
i) Ripple factor ii) Peak Inverse voltage iii) Efficiency
iv) TUF v) Form factor vi) Peak factor.
Contd….2
Set No:
2
Code No:RR12302 -2- Set No:2
5.a) Define the following BJT switching times with suitable sketches..
i) Delay time, ii) Turn-on Time iii) Storage Time
iv) Fall time v) turn-off time
b) What are the bias compensation techniques? Explain the operation of one among
them.
c) An n-p-n transistor with b = 50 is used in a CE circuit with VCC = 10V, and RC =
2KW. The bias is obtained by connecting a 100KW resistance from collector to
base. Assume VBE=0V. Find the Quiescent point.
6. a) List out different distortions that occur in amplifiers and discuss.
b) Enumerate the effect of negative feedback on the various characteristics of the
amplifier.
Draw the circuit diagram of an emitter follower circuit and mention what type of
feedback is employed? Justify your answer.
7.a) Give the circuit diagram of a scale changer circuit using OP-AMP and explain its
operation.
b) Design an astable multivibrator circuit using, silicon BJTs for the given
specifications: Vcc = 15V,
FEmin h = 40,
Csat I = 2mA, tON = tOFF = 200msec. Assume
necessary data.
8. a) Realize Full-adder using logic gates.
b) Explain the principle of operation of D-to-A converter.
c) Simplify the following functions
(i) A¢BC¢ + A¢C¢D + A¢B¢D¢ + AC + BCD¢
(ii) A¢B¢D¢ + A¢CD + A¢BC.
**********
Code No:RR12302
I B.Tech Regular Examination, May/June 2004
ELECTRICAL AND ELECTRONICS ENGINEERING
(Bio Technology)
Time: 3 hours. Max.Marks:80
Answer any FIVE questions.
All questions carry equal marks.
- - -
1. a) Define the terms i) active power ii) reactive power and iii) apparent power,
and give the expressions for the same.
b) A single phase motor operating at 440V, 50 HZ supply is developing 10Kw
with an efficiency of 84% and power factor 0.7 lag. Calculate (a) the input KVA
and active power, and reactive power.
2.a) Discuss the classification of d.c generators with suitable diagrams, and give the
practical applications of each generator.
b) A 10Kw shunt generator supplies load at a terminal voltage of 200 volts. The
shunt field resistance is 100 ohms and armature resistance is 0.1 ohm. Calculate
the e.m.f induced in the generator.
3.a) Determine the currents I1,I2 and I3 for the circuit shown below.
b) What are the specifications of any p-n diode.
c) Explain current components in a diode.
4.a) Sketch typical SCR forward and reverse characteristics.
b) Identify all regions of the characteristics and all important current and voltage
levels.
c) Explain the shape of the curves in terms of the SCR two transistor equivalent
Circuit.
d) Explain why always silicon but not Germanium is used in the construction of
SCR.
e) Obtain the expression for total current through SCR and Triac.
Contd….2
Set No:
3
Code No:RR12302 -2- Set No:3
5.a) Define different stability factors of biasing circuits using BJT.
b) List out different transistor biasing methods and compare their merits and
demerits.
c) Write short notes on
i) Thermal runaway ii) Early effect
6. a) Give the advantages of negative feedback amplifier.
b) Draw the circuit of a voltage shunt feedback amplifier and explain.
c) When the negative feedback is applied to an amplifier of gain 100, the overall
gain falls to 50. Calculate (i) the feedback factor ‘b’ (ii) If the same feedback
factor is maintained, find the value of amplifier gain required if the overall gain is
to be 75.
7.a) Derive an expression for the O/P voltage of OP AMP integrator circuit.
b) Explain the principle of operation of transistorized RC phase shift oscillator.
8. a) Explain with a block diagram the major blocks of a digital computer.
b) Implement the following with either NAND or NOR gates. Use only 4 gates only
the normal inputs are available.
F = w¢xz + w¢yz + x¢yz¢ + wxy¢z.
c) With a circuit diagram, explain Counter type A-to-D converter.
**********
Code No:RR12302
I B.Tech Regular Examination, May/June 2004
ELECTRICAL AND ELECTRONICS ENGINEERING
(Bio Technology)
Time: 3 hours. Max.Marks:80
Answer any FIVE questions.
All questions carry equal marks.
- - -
1.a) Explain what do you understand by
i) unidirectional current ii) alternating current iii) sinusoidal a.c. current
b) Define the terms i) R.M.S value ii) time period iii) frequency iv) average value.
c) Find out average value and root mean square value of output waveform of full
wave rectifier circuit. Assume the waveform has maximum voltage of 24V with
100Hz frequency.
2.a) Derive the torque equation of a d.c motor.
b) A 4-pole wave wound d.c armature has 294 conductors. Find (a) Flux per pole
to generate 230V at 1500 r.p.m. (b) Electromagnetic torque at this flux when
armature current is 120 A.
3.a) Explain how an n-type semiconductor is formed. Name different donor impurities
used.
b) (i) Find the conductivity of intrinsic silicon at 3000K.
(ii)If donor impurity is added to the extent of 1 impurity atom in 108 silicon
atoms, find the conductivity. It is given that at 3000K,
ni = 1.5´1010 /Cm3, m p = 500Cm2 / v - s, m n = 1300Cm2 /V - S.
4.a) Describe the basic structure of DIAC. Draw its volt-ampere characteristics and
explain.
b) Define and explain the following terms of SCR
i) Turn-on-time ii) Turn-off-time
c) Draw the two transistor representation of SCR and explain.
5.a) Draw the static drain characteristics and transfer characteristics of an N-channel
MOSFET and explain the shape of the curves qualitatively.
b) Explain the following
i) BJT Switching times with suitable sketches.
ii) Early effect and its consequences.
6. a) Draw the circuit of a current shunt feedback amplifier and explain.
b) An amplifier has a gain of 10,000 without feedback. The gain is reduced to 50
with negative feedback. Find the feedback factor.
c) Explain the principle of operations of Tuned amplifiers.
7.a) A FET phase shift oscillator has gm = 500ms, and rd = 30kW. The feedback
resistance is 100kW, and the capacitor value is 64.97pF. Calculate the frequency
of oscillations and the value of RD. Draw the corresponding circuit diagram.
b) Explain about symmetrical and asymmetrical triggering methods in
mutlivibrators.
8.a) Give the Boolean functions: F= xy + x¢y¢ +y¢z
(i) Implement with only OR and NOT gates.
(ii) Implement with only AND and NOT gates.
b) Explain the principle of master-slave JK flip-flop.
c) Find the complement of given function and reduce it to a minimum number of
literals. (BC¢+A¢D) (AB¢+CD¢)
***********
I B.Tech Regular Examination, May/June 2004
ELECTRICAL AND ELECTRONICS ENGINEERING
(Bio Technology)
Time: 3 hours. Max.Marks:80
Answer any FIVE questions.
All questions carry equal marks.
- - -
1. a) Write down the expression for the instantaneous power, and hence derive the
equation for the average power.
b) A series R-L-C circuit consists of 100 ohms resistor and an inductor of 0.318
Henry and a capacitor of unknown value. This circuit is supplied by 230V, 50 HZ
supply and draws a current of 2.3 ohms, and the current is in phase with the
supply voltage. Find i) the value of the capacitance, and the power supplied by the
source.
2.a) Derive the equation for the voltage generated in a d.c generator.
b) A 2 pole d.c generator has 200 conductors on its armature. It is driven by a
prime mover at a constant speed of 600 r.p.m. If the flux per pole is 0.1 wb,
calculate the emf generated.
3.a) Prove that the Fermi level for p-type semiconductor is given by
. ln
= +
A
V
F V N
N
E E KT
b) In a p-type semiconductor, if the concentration of acceptor atoms is increased by a
factor 10, find the shift in the position of Fermi level. Assume KT=0.03ev.
4.a) A HWR has a load of 3.5KW. If the diode resistance and secondary coil
resistance together have a resistance of 800W and the input voltage has a signal
voltage of peak value 240v, Calculate
i) Peak, average and RMS value of current flowing.
ii) dc power output
iii) AC power input
iv) Efficiency of the rectifier.
b) Compare Half wave, Center tapped full wave and Bridge rectifiers.
5.a) Draw a self bias circuit using n-p-n transistor and derive expression for stability
factor S'.
b) A transistor with b = 100 is to be used in a CE configuration with collector-tobase
bias. If RC = 1KW and Va = 10V. Assume VBE = 0 and it is required to have
a quiescent collector-to-emitter voltage is 4V. Find the value of RB and the
stability factors S and S'.
Contd….2
Set No:
1
Code No:RR12302 -2- Set No:1
6. a) Compare the differences between voltage amplifiers and power amplifiers.
b) Show that the maximum theoretical efficiency of class B push-pull amplifiers is
78.5%.
c) Draw the circuit of a transformer coupled power amplifier and explain its
operations with help of load-line analysis.
7.a) Draw the internal diagram of OP-AMP. Explain the function of each block.
b) What do you understand about the term “Virtual ground”? Give the circuit
diagram for differentiate circuit using OP-AMP and prove that a triangular
waveform with frequency 5KHz is converted into rectangular waveform of the
same frequency.
8. a) Realize Exclusive-OR gate using minimum number of NAND gates.
b) Realize SR flip-flop using NAND gates.
c) Explain the principle of decade counter and realize it using JK-flipflops.
d) Realize exclusive –OR gate using basic gates.
***********
Code No:RR12302
I B.Tech Regular Examination, May/June 2004
ELECTRICAL AND ELECTRONICS ENGINEERING
(Bio Technology)
Time: 3 hours. Max.Marks:80
Answer any FIVE questions.
All questions carry equal marks.
- - -
1. Consider a general A.C circuit in which the current leads the applied voltage
by an angle f . Write the equation for the voltage and current and hence derive the
equation for the power. Also plot the voltage, current and power wave forms.
2.a) Explain the process of voltage build up in a self-excited d.c machine.
b) List out the various conditions to be satisfied for voltage build up process in a
self-excited machine, and write down remedies if the conditions fail.
3.a) Draw the V-I characteristics of p-n diode and explain.
b) (i) What is the current in the diode shown in the fig.
(ii) Calculate the load voltage load power, diode power and total power in the
above circuit.
c) Explain how p-n junction diode act as a rectifier.
4.a) In a bridge rectifier, the transformer is connected to 220V, 60Hz mains and the
turns ratio of the step down transformer is 11:1. Load resistance is 800 W.
Assuming the diode is ideal, find
i) Idc
ii) Voltage across the load
iii) PIV
b) Explain the following terms:
i) Ripple factor ii) Peak Inverse voltage iii) Efficiency
iv) TUF v) Form factor vi) Peak factor.
Contd….2
Set No:
2
Code No:RR12302 -2- Set No:2
5.a) Define the following BJT switching times with suitable sketches..
i) Delay time, ii) Turn-on Time iii) Storage Time
iv) Fall time v) turn-off time
b) What are the bias compensation techniques? Explain the operation of one among
them.
c) An n-p-n transistor with b = 50 is used in a CE circuit with VCC = 10V, and RC =
2KW. The bias is obtained by connecting a 100KW resistance from collector to
base. Assume VBE=0V. Find the Quiescent point.
6. a) List out different distortions that occur in amplifiers and discuss.
b) Enumerate the effect of negative feedback on the various characteristics of the
amplifier.
Draw the circuit diagram of an emitter follower circuit and mention what type of
feedback is employed? Justify your answer.
7.a) Give the circuit diagram of a scale changer circuit using OP-AMP and explain its
operation.
b) Design an astable multivibrator circuit using, silicon BJTs for the given
specifications: Vcc = 15V,
FEmin h = 40,
Csat I = 2mA, tON = tOFF = 200msec. Assume
necessary data.
8. a) Realize Full-adder using logic gates.
b) Explain the principle of operation of D-to-A converter.
c) Simplify the following functions
(i) A¢BC¢ + A¢C¢D + A¢B¢D¢ + AC + BCD¢
(ii) A¢B¢D¢ + A¢CD + A¢BC.
**********
Code No:RR12302
I B.Tech Regular Examination, May/June 2004
ELECTRICAL AND ELECTRONICS ENGINEERING
(Bio Technology)
Time: 3 hours. Max.Marks:80
Answer any FIVE questions.
All questions carry equal marks.
- - -
1. a) Define the terms i) active power ii) reactive power and iii) apparent power,
and give the expressions for the same.
b) A single phase motor operating at 440V, 50 HZ supply is developing 10Kw
with an efficiency of 84% and power factor 0.7 lag. Calculate (a) the input KVA
and active power, and reactive power.
2.a) Discuss the classification of d.c generators with suitable diagrams, and give the
practical applications of each generator.
b) A 10Kw shunt generator supplies load at a terminal voltage of 200 volts. The
shunt field resistance is 100 ohms and armature resistance is 0.1 ohm. Calculate
the e.m.f induced in the generator.
3.a) Determine the currents I1,I2 and I3 for the circuit shown below.
b) What are the specifications of any p-n diode.
c) Explain current components in a diode.
4.a) Sketch typical SCR forward and reverse characteristics.
b) Identify all regions of the characteristics and all important current and voltage
levels.
c) Explain the shape of the curves in terms of the SCR two transistor equivalent
Circuit.
d) Explain why always silicon but not Germanium is used in the construction of
SCR.
e) Obtain the expression for total current through SCR and Triac.
Contd….2
Set No:
3
Code No:RR12302 -2- Set No:3
5.a) Define different stability factors of biasing circuits using BJT.
b) List out different transistor biasing methods and compare their merits and
demerits.
c) Write short notes on
i) Thermal runaway ii) Early effect
6. a) Give the advantages of negative feedback amplifier.
b) Draw the circuit of a voltage shunt feedback amplifier and explain.
c) When the negative feedback is applied to an amplifier of gain 100, the overall
gain falls to 50. Calculate (i) the feedback factor ‘b’ (ii) If the same feedback
factor is maintained, find the value of amplifier gain required if the overall gain is
to be 75.
7.a) Derive an expression for the O/P voltage of OP AMP integrator circuit.
b) Explain the principle of operation of transistorized RC phase shift oscillator.
8. a) Explain with a block diagram the major blocks of a digital computer.
b) Implement the following with either NAND or NOR gates. Use only 4 gates only
the normal inputs are available.
F = w¢xz + w¢yz + x¢yz¢ + wxy¢z.
c) With a circuit diagram, explain Counter type A-to-D converter.
**********
Code No:RR12302
I B.Tech Regular Examination, May/June 2004
ELECTRICAL AND ELECTRONICS ENGINEERING
(Bio Technology)
Time: 3 hours. Max.Marks:80
Answer any FIVE questions.
All questions carry equal marks.
- - -
1.a) Explain what do you understand by
i) unidirectional current ii) alternating current iii) sinusoidal a.c. current
b) Define the terms i) R.M.S value ii) time period iii) frequency iv) average value.
c) Find out average value and root mean square value of output waveform of full
wave rectifier circuit. Assume the waveform has maximum voltage of 24V with
100Hz frequency.
2.a) Derive the torque equation of a d.c motor.
b) A 4-pole wave wound d.c armature has 294 conductors. Find (a) Flux per pole
to generate 230V at 1500 r.p.m. (b) Electromagnetic torque at this flux when
armature current is 120 A.
3.a) Explain how an n-type semiconductor is formed. Name different donor impurities
used.
b) (i) Find the conductivity of intrinsic silicon at 3000K.
(ii)If donor impurity is added to the extent of 1 impurity atom in 108 silicon
atoms, find the conductivity. It is given that at 3000K,
ni = 1.5´1010 /Cm3, m p = 500Cm2 / v - s, m n = 1300Cm2 /V - S.
4.a) Describe the basic structure of DIAC. Draw its volt-ampere characteristics and
explain.
b) Define and explain the following terms of SCR
i) Turn-on-time ii) Turn-off-time
c) Draw the two transistor representation of SCR and explain.
5.a) Draw the static drain characteristics and transfer characteristics of an N-channel
MOSFET and explain the shape of the curves qualitatively.
b) Explain the following
i) BJT Switching times with suitable sketches.
ii) Early effect and its consequences.
6. a) Draw the circuit of a current shunt feedback amplifier and explain.
b) An amplifier has a gain of 10,000 without feedback. The gain is reduced to 50
with negative feedback. Find the feedback factor.
c) Explain the principle of operations of Tuned amplifiers.
7.a) A FET phase shift oscillator has gm = 500ms, and rd = 30kW. The feedback
resistance is 100kW, and the capacitor value is 64.97pF. Calculate the frequency
of oscillations and the value of RD. Draw the corresponding circuit diagram.
b) Explain about symmetrical and asymmetrical triggering methods in
mutlivibrators.
8.a) Give the Boolean functions: F= xy + x¢y¢ +y¢z
(i) Implement with only OR and NOT gates.
(ii) Implement with only AND and NOT gates.
b) Explain the principle of master-slave JK flip-flop.
c) Find the complement of given function and reduce it to a minimum number of
literals. (BC¢+A¢D) (AB¢+CD¢)
***********
ELECTRICAL AND ELECTRONICS ENGINEERING-SUPPLY 2K3
Code No:RR-12302
I B.Tech. Supplementary Examinations, November-2003
ELECTRICAL AND ELECTRONICS ENGINEERING
(Bio-Technology)
Time:3 hours Max Marks:80
Answer any Five Questions
All questions carry equal marks.
----
1.a) Derive an expression for the total power in a 3-phase circuit in terms of line
voltages and line currents. Show that the power is same whether the load is delta
connected or star connected.
b) A 3-phase balanced star-connected load consists of 100 ohms resistance connected
across a 220V, 3-phase supply. Determine the line currents and total power
consumed.
2.a) Give the constructional features of “CORE” and “Shell” types of transformers, and
give the advantages and disadvantages of each type.
b) A 5 KVA, 2300 / 230V, 50 HZ transformer was tested for the iron loss with normal
excitation and copper losses at full load, and these were found to be 40 watts and 112
watts respectively. Calculate efficiency of the transformer at (i) full load (ii) half full
load. Assume the power factor of the load as 0.8.
3.a) Prove that the concentration of holes in an intrinsic semiconductor is given by
E E KT
v
p N e F V = -( - ) / .
b) Prove that for intrinsic semiconductor 2
i n is proportional to E KT GO T e 3 - / .
4.a) Draw the circuit diagram of half wave rectifier and explain its operation.
b) A half wave rectifier is fed by 220V, 50Hz via a step down transformer of turns ratio
11:1 find (i) the output d.c. and (ii) peak inverse voltage under no load condition.
5.a) Explain qualitatively the three consequences of base-width modulation.
b) Derive relationship between IC and IB for a CE transistor configuration in the active
region.
c) Sketch a family of CE input and output characteristics for the given transistor (npn)
and explain the shape of the curves qualitatively.
6. a) Classify and define the amplifiers depending on the conduction period and sketch the
input and output waveforms.
b) Show that the maximum theoretical efficiency of a class A power amplifier is 50%.
7.a) What kind of feedback is incorporated in the wien bridge oscillator circuit? And why?
b) In a colpitts oscillator using FET, the frequency of oscillations is observed to be
2.5MHz. Oscillator uses L=10mH, C1 = 0.02mF. Find (i) the value of C2 (ii) If L is
doubled the new value of frequency oscillations.
c) Explain about the applications of OPAMP.
8.a) State and prove D Morgau’s theorems.
b) Realize NOR gate using minimum number of NAND gates.
c) Find the 2’S complement of (46)10.
@@@@@
Set No.
1
Code No:RR-12302
I B.Tech. Supplementary Examinations, November-2003
ELECTRICAL AND ELECTRONICS ENGINEERING
(Bio-Technology)
Time:3 hours Max Marks:80
Answer any Five Questions
All questions carry equal marks.
----
1. With a neat sketch explain the construction and working principle of permanent
magnet moving coil instrument. Derive the torque equation. Explain with suitable
circuits, how PMMC is used as voltmeter?
2.a) Does the induction motor have any similarities with the transformer? Compare
the similarities and differences between them.
b) A 20h.p, 400V, 50HZ, 3-phase induction motor has an efficiency of 80% and working
at 0.7p.f. The motor is connected to 400 volts, 3-phase supply calculate the current
drawn by the motor from the mains.
3.a) Explain the Law of junction for p-n diode.
b) Explain Avalanche and Zener break downs and compare.
c) Derive Diode current equation.
4.a) A full wave bridge rectifier is fed with 220v, 50Hz, through a step-down transformer
of turns ratio 11:1. Assuming ideal diode find the i)d.c. output voltage ii) peak
inverse voltage iii)Rectifier efficiency. The load resistance is 100W.
b) What is ripple factor? Show that the ripple factor for full wave rectifier is 0.482.
5.a) Sketch a family of drain and mutual characteristics and explain the shape of the
curves qualitatively for a JFET.
b) For a source self-bias circuit if ID = 0.8 mA, IDSS = 1.65 mA and VP = -2V find VGS.
6. a) Draw the circuit diagram of push-pull amplifier circuit and explain its operation. List
out the merits of push pull-amplifier.
b) What is meant by crossover distortion – explain.
7. a) Explain the working of Hartley oscillator circuit. Derive the expression for the
frequency.
b) A collector coupled mono stable multi vibrator consists of NPN Si transistors with hFE
of 30, rbb' = 200W, VCC = 10v, VBE = -2v, RC = 5k, RC1 = RC2 = 1k, R=10k, C=0.1mF,
R2=10k, Rb1 = 20k. Calculate the base and collector currents and voltages.
8.a) Explain the working of SR-flipflop.
b) Implement F = A¢B¢C¢ + ABC¢ with NAND gates.
c) Explain Race around conditioning J-K flip flop and how is it eliminated.
@@@@@
Set No.
2
Code No:RR-12302
I B.Tech. Supplementary Examinations, November-2003
ELECTRICAL AND ELECTRONICS ENGINEERING
(Bio-Technology)
Time:3 hours Max Marks:80
Answer any Five Questions
All questions carry equal marks.
----
1. With a neat sketch explain the construction and working principle of moving iron
(M.I) type instrument. Write down the torque equation.
2.a) Explain the constructional details of a synchronous machine giving the reasons for
making two types of rotors.
b) Explain auxiliary motor starting of synchronous motors.
3.a) Sketch the forward and reverse characteristics of Ge and Si diodes and compare.
b) Design a voltage regulator that will maintain output voltage of 20V across 1.2kW load
with input that varies between 30 and 50V.
c) Derive the expression for Transition capacitance of Diode.
4.a) What are the principle feature of a bridge rectifier. Explain its operation with neat
circuit diagram.
b) Describe the characteristics of a triac.
5.a) Draw a family of drain characteristics and mutual characteristics of an n-channel FET
and explain the shape of the curves qualitatively.
b) Define FET parameters and derive the relationship between them.
6. a) With the help of block diagrams, explain the four different feed back topologies.
b) Draw the circuit of a voltage series feedback amplifier with BJT. What is the effect
of this feedback on Ri and R0.
7.a) Discuss and explain the basic circuit of an LC oscillator and derive the condition for
the oscillations.
b) Compare various multivibrators.
8.a) Explain the principle of 4-bit ripple counter with a diagram.
b) Obtain the truth table of the function F = xy + xy¢ + y¢z
c) Draw the circuit diagram of R-2R ladder D-to-A converter and explain its principle.
@@@@@
Set No.
3
Code No:RR-12302
I B.Tech. Supplementary Examinations, November-2003
ELECTRICAL AND ELECTRONICS ENGINEERING
(Bio-Technology)
Time:3 hours Max Marks:80
Answer any Five Questions
All questions carry equal marks.
----
1.a) With a neat sketch explain the construction and principle of operation of
dynamometer type watt meter.
b) Two 40w tube lights are ON for a period of six hours a day. Calculate the total energy
consumed by them in a month?
2.a) How e.m.f is induced in the armature of an alternator? What are the factors that
cause a change of the alternator terminal voltage.
b) A 3-phase, 10 pole, star-connected alternator is running at 720 r.p.m. It has a total of
1200 stator conductors the flux per pole 0.056 wb. Determine the induced e.m.f per
phase. Also calculate the line value.
3.a) Explain the formation of depletion layer in an unbiased p-n junction. How does it vary
with (i) bias and (ii) with temperature.
b) Explain about grown and alloy junctions in case of a p-n junction diode.
4.a) Draw the block diagram of a regulated power supply and explain its operation.
b) Determine the value of ripple factor for the output of a Half wave rectifier without
filter.
5.a) Draw the circuit diagram of a fixed bias circuit and derive the expression for stability
factor S. Why this circuit is thermally not stable – Explain.
b) An n-p-n transistor with b = 50 is used in a CE circuit with VCC=10V, RC = 2KW.
The bias is obtained by connecting a 100 KW. resistance from collector to base.
Assume VBE=0V. Find (i) the Quiescent point (ii) the Stability factor S.
6. a) Define class A, B, AB, B and C operation of amplifiers.
b) Draw the circuit diagram of a push-pull amplifier and explain how even harmonics
are eliminated.
c) Derive the relation between gain with feed back and without feedback.
7.a) Explain the operation of monostable multi vibrator with relevant waveforms.
b) How Frequency stability can be improved in the oscillators? Explain.
c) For phase shift oscillator, the feedback network uses R=6kW and C=1500pF. The
transistorized amplifier used, has a collector resistance of 18kW. Calculate the
frequency of oscillations and minimum value of hfe of the transistor.
8.a) Explain the principle of Half-adder. Draw various implementations of sum and carry
of Half-adder.
b) Implement AND and OR gate using discrete components.
c) How do you convert JK-flip-flop to T and D flip-flops.
@@@@@
Set No.
4
I B.Tech. Supplementary Examinations, November-2003
ELECTRICAL AND ELECTRONICS ENGINEERING
(Bio-Technology)
Time:3 hours Max Marks:80
Answer any Five Questions
All questions carry equal marks.
----
1.a) Derive an expression for the total power in a 3-phase circuit in terms of line
voltages and line currents. Show that the power is same whether the load is delta
connected or star connected.
b) A 3-phase balanced star-connected load consists of 100 ohms resistance connected
across a 220V, 3-phase supply. Determine the line currents and total power
consumed.
2.a) Give the constructional features of “CORE” and “Shell” types of transformers, and
give the advantages and disadvantages of each type.
b) A 5 KVA, 2300 / 230V, 50 HZ transformer was tested for the iron loss with normal
excitation and copper losses at full load, and these were found to be 40 watts and 112
watts respectively. Calculate efficiency of the transformer at (i) full load (ii) half full
load. Assume the power factor of the load as 0.8.
3.a) Prove that the concentration of holes in an intrinsic semiconductor is given by
E E KT
v
p N e F V = -( - ) / .
b) Prove that for intrinsic semiconductor 2
i n is proportional to E KT GO T e 3 - / .
4.a) Draw the circuit diagram of half wave rectifier and explain its operation.
b) A half wave rectifier is fed by 220V, 50Hz via a step down transformer of turns ratio
11:1 find (i) the output d.c. and (ii) peak inverse voltage under no load condition.
5.a) Explain qualitatively the three consequences of base-width modulation.
b) Derive relationship between IC and IB for a CE transistor configuration in the active
region.
c) Sketch a family of CE input and output characteristics for the given transistor (npn)
and explain the shape of the curves qualitatively.
6. a) Classify and define the amplifiers depending on the conduction period and sketch the
input and output waveforms.
b) Show that the maximum theoretical efficiency of a class A power amplifier is 50%.
7.a) What kind of feedback is incorporated in the wien bridge oscillator circuit? And why?
b) In a colpitts oscillator using FET, the frequency of oscillations is observed to be
2.5MHz. Oscillator uses L=10mH, C1 = 0.02mF. Find (i) the value of C2 (ii) If L is
doubled the new value of frequency oscillations.
c) Explain about the applications of OPAMP.
8.a) State and prove D Morgau’s theorems.
b) Realize NOR gate using minimum number of NAND gates.
c) Find the 2’S complement of (46)10.
@@@@@
Set No.
1
Code No:RR-12302
I B.Tech. Supplementary Examinations, November-2003
ELECTRICAL AND ELECTRONICS ENGINEERING
(Bio-Technology)
Time:3 hours Max Marks:80
Answer any Five Questions
All questions carry equal marks.
----
1. With a neat sketch explain the construction and working principle of permanent
magnet moving coil instrument. Derive the torque equation. Explain with suitable
circuits, how PMMC is used as voltmeter?
2.a) Does the induction motor have any similarities with the transformer? Compare
the similarities and differences between them.
b) A 20h.p, 400V, 50HZ, 3-phase induction motor has an efficiency of 80% and working
at 0.7p.f. The motor is connected to 400 volts, 3-phase supply calculate the current
drawn by the motor from the mains.
3.a) Explain the Law of junction for p-n diode.
b) Explain Avalanche and Zener break downs and compare.
c) Derive Diode current equation.
4.a) A full wave bridge rectifier is fed with 220v, 50Hz, through a step-down transformer
of turns ratio 11:1. Assuming ideal diode find the i)d.c. output voltage ii) peak
inverse voltage iii)Rectifier efficiency. The load resistance is 100W.
b) What is ripple factor? Show that the ripple factor for full wave rectifier is 0.482.
5.a) Sketch a family of drain and mutual characteristics and explain the shape of the
curves qualitatively for a JFET.
b) For a source self-bias circuit if ID = 0.8 mA, IDSS = 1.65 mA and VP = -2V find VGS.
6. a) Draw the circuit diagram of push-pull amplifier circuit and explain its operation. List
out the merits of push pull-amplifier.
b) What is meant by crossover distortion – explain.
7. a) Explain the working of Hartley oscillator circuit. Derive the expression for the
frequency.
b) A collector coupled mono stable multi vibrator consists of NPN Si transistors with hFE
of 30, rbb' = 200W, VCC = 10v, VBE = -2v, RC = 5k, RC1 = RC2 = 1k, R=10k, C=0.1mF,
R2=10k, Rb1 = 20k. Calculate the base and collector currents and voltages.
8.a) Explain the working of SR-flipflop.
b) Implement F = A¢B¢C¢ + ABC¢ with NAND gates.
c) Explain Race around conditioning J-K flip flop and how is it eliminated.
@@@@@
Set No.
2
Code No:RR-12302
I B.Tech. Supplementary Examinations, November-2003
ELECTRICAL AND ELECTRONICS ENGINEERING
(Bio-Technology)
Time:3 hours Max Marks:80
Answer any Five Questions
All questions carry equal marks.
----
1. With a neat sketch explain the construction and working principle of moving iron
(M.I) type instrument. Write down the torque equation.
2.a) Explain the constructional details of a synchronous machine giving the reasons for
making two types of rotors.
b) Explain auxiliary motor starting of synchronous motors.
3.a) Sketch the forward and reverse characteristics of Ge and Si diodes and compare.
b) Design a voltage regulator that will maintain output voltage of 20V across 1.2kW load
with input that varies between 30 and 50V.
c) Derive the expression for Transition capacitance of Diode.
4.a) What are the principle feature of a bridge rectifier. Explain its operation with neat
circuit diagram.
b) Describe the characteristics of a triac.
5.a) Draw a family of drain characteristics and mutual characteristics of an n-channel FET
and explain the shape of the curves qualitatively.
b) Define FET parameters and derive the relationship between them.
6. a) With the help of block diagrams, explain the four different feed back topologies.
b) Draw the circuit of a voltage series feedback amplifier with BJT. What is the effect
of this feedback on Ri and R0.
7.a) Discuss and explain the basic circuit of an LC oscillator and derive the condition for
the oscillations.
b) Compare various multivibrators.
8.a) Explain the principle of 4-bit ripple counter with a diagram.
b) Obtain the truth table of the function F = xy + xy¢ + y¢z
c) Draw the circuit diagram of R-2R ladder D-to-A converter and explain its principle.
@@@@@
Set No.
3
Code No:RR-12302
I B.Tech. Supplementary Examinations, November-2003
ELECTRICAL AND ELECTRONICS ENGINEERING
(Bio-Technology)
Time:3 hours Max Marks:80
Answer any Five Questions
All questions carry equal marks.
----
1.a) With a neat sketch explain the construction and principle of operation of
dynamometer type watt meter.
b) Two 40w tube lights are ON for a period of six hours a day. Calculate the total energy
consumed by them in a month?
2.a) How e.m.f is induced in the armature of an alternator? What are the factors that
cause a change of the alternator terminal voltage.
b) A 3-phase, 10 pole, star-connected alternator is running at 720 r.p.m. It has a total of
1200 stator conductors the flux per pole 0.056 wb. Determine the induced e.m.f per
phase. Also calculate the line value.
3.a) Explain the formation of depletion layer in an unbiased p-n junction. How does it vary
with (i) bias and (ii) with temperature.
b) Explain about grown and alloy junctions in case of a p-n junction diode.
4.a) Draw the block diagram of a regulated power supply and explain its operation.
b) Determine the value of ripple factor for the output of a Half wave rectifier without
filter.
5.a) Draw the circuit diagram of a fixed bias circuit and derive the expression for stability
factor S. Why this circuit is thermally not stable – Explain.
b) An n-p-n transistor with b = 50 is used in a CE circuit with VCC=10V, RC = 2KW.
The bias is obtained by connecting a 100 KW. resistance from collector to base.
Assume VBE=0V. Find (i) the Quiescent point (ii) the Stability factor S.
6. a) Define class A, B, AB, B and C operation of amplifiers.
b) Draw the circuit diagram of a push-pull amplifier and explain how even harmonics
are eliminated.
c) Derive the relation between gain with feed back and without feedback.
7.a) Explain the operation of monostable multi vibrator with relevant waveforms.
b) How Frequency stability can be improved in the oscillators? Explain.
c) For phase shift oscillator, the feedback network uses R=6kW and C=1500pF. The
transistorized amplifier used, has a collector resistance of 18kW. Calculate the
frequency of oscillations and minimum value of hfe of the transistor.
8.a) Explain the principle of Half-adder. Draw various implementations of sum and carry
of Half-adder.
b) Implement AND and OR gate using discrete components.
c) How do you convert JK-flip-flop to T and D flip-flops.
@@@@@
Set No.
4
BASIC ELECTRICAL AND ELECTRONICS ENGINEERING SUPPLY 2K7 RO5
1. (a) Determine the voltage
VAB in the circuit shown in the figure 1a Figure 1a (b) Find the power dissipated in 40 ohm resistor of figure 1b shown. [10+6] Figure 1b
2. (a) Derive the torque equation of a D.C motor. (b) A 4-pole wave wound D.C armature has 294 conductors. Find i. Flux per pole to generate 230 V at 1500 r.p.m. ii. Electromagnetic torque at this flux when armature current is 120 A.[8+8]
3. (a) Determine the range of input voltage that maintains an output voltage of 10 V at the output for the regulator shown in the figure 3a Figure 3a (b) Explain the applications of Zener diode. (c) Explain static and Dynamic Resistance of a diode. [4+8+4]
4. (a) The half wave rectifier shown in the figure 4a is fed with a sinusoidal voltage V=20 sin100t. i. Sketch the output waveform. ii. Determine the DC output voltage assuming ideal diode behaviour. iii. Repeat the calculations assuming the simplified diode (silicon) model. Figure 4a (b) Draw the circuit diagram of full wave rectifier having two diodes and explain its operation. [8+8]
5. (a) Sketch a family of drain and mutual characteristics and explain the shape of the curves qualitatively for a JFET. (b) For a source self-bias circuit if ID = 0.8 mA, IDSS = 1.65 mA and VP = –2V find VGS. [8+8]
6. (a) With the help of block diagrams, explain the four different feed back topologies. (b) Draw the circuit of a voltage series feedback amplifier with BJT. What is the effect of this feedback as Ri and R0. [6+10]
7. (a) Explain the operation of an integrator using OP-AMPs. (b) Distinguish between positive and negative feedbacks. (c) List out the characteristics of OP-AMP. [6+4+6]
8. (a) Realize Full-adder using logic gates. (b) Explain the principle of operation of D to A converter. (c) Simplify the following functions i. A′BC′ + A′C′D + A′B′D′ + AC + BCD′ ii. A′B′D′ + A′CD + A′BC.
SET :2
1. With a neat sketch explain the construction and working principle of moving iron (M.I) type instrument. Write down the torque equation. [16]
2. (a) Does the induction motor have any similarities with the transformer. Compare the similarities and differences between them. (b) A 20 h.p, 400 V, 50 Hz, 3-phase induction motor has an efficiency of 80% and working at 0.7 p.f. The motor is connected to 400 Volts, 3-phase supply calculate the current drawn by the motor from the mains. [8+8]
3. (a) For the network shown in the figure 3(a)i determine the range of RL and IL that will result in VRL being maintained at 10 V. i. Determine the maximum Wattage rating of the diode. Figure 3(a)i ii. The reverse saturation current of the diode is 1 μA. Its peak inverse Voltage is 500V. Find ri, Vo that PIV is not exceeded. show in figure 3(a)ii & figure 3(a)iii Figure 3(a)ii Figure 3(a)iii
4. (a) A sinusoidal voltage of peak value 40V and frequency 50 Hz is applied to HWR using PN diode. The total load resistor is 800 . Neglecting cut in voltage and using idealized characteristic for the diode with Rf=8 and Rr=α calculate i. Peak D.C and RMS values of load current ii. D.C and A.C output power iii. Rectifier efficiency iv. Ripple factor. (b) Derive the formulas used in the above problem. [8+8]
5. (a) Draw the static drain characteristics and transfer characteristics of an N- channel MOSFET and explain the shape of the curves qualitatively. (b) Explain the following i. BJT Switching times with suitable sketches. ii. Early effect and its consequences. [6+10]
6. (a) Classify and define the amplifiers depending on the conduction period and sketch the input and output waveforms. (b) Show that the maximum theoretical efficiency of a class A power amplifier is 50%. [8+8]
7. (a) Find the resistance R and hfe for the transistor to provide a resonating frequency of 5 kHz of a transistorized phase shift oscillator. The biasing resistances are 25 kand 47 k. The load resistance is 10. The capacitor in the tank circuit is 1000 pF which hie of the transistor is 2 k. (b) Explain the role of commutating capacitors in multivibrator circuits. (c) Design an Astable multivibrator circuit with 50% duty cycle and f=2 KHz, VCC=10V, VBE(Sat) = 0.6V, VCE(Sat) = 0.3V. Using N-P-N Si transistors. [6+2+8]
8. (a) Explain with a block diagram the major blocks of a digital computer. (b) Implement the following with either NAND or NOR gates. Use only 4 gates only the normal inputs are available. F = w′xz + w′yz + x′yz′ + wxy′z. (c) With a circuit diagram, explain Counter type A to D converter. [4+6+6]
SET :3
1. (a) Define resistance. (b) State and explain Ohms Law. (c) Find out the equivalent resistance of the following circuit between the points A and B (all values are in ohms) as shown in the figure 1c [2+4+4] (d) Find the impedance between ‘X’ and ‘Y’ points of the figure 1d shown.
2. (a) Give the constructional features of “CORE” and “Shell” types of transformers, and give the advantages and disadvantages of each type. (b) A 5 KVA, 2300 / 230 V, 50 Hz transformer was tested for the iron loss with normal excitation and copper losses at full load, and these were found to be 40 Watts and 112 Watts respectively. Calculate efficiency of the transformer at i. full load. ii. half full load. Assume the power factor of the load as 0.8. [8+8]
3. (a) Draw the equivalent circuits of i. ideal diode ii. Simplified model of diode. iii. piece wise linear model of diode. Draw their characteristics. (b) Derive the expression for diffusion capacitance in a diode. [10+6]
4. (a) The half wave rectifier shown in the figure 4a is fed with a sinusoidal voltage V=20 sin100t. i. Sketch the output waveform. ii. Determine the DC output voltage assuming ideal diode behaviour. iii. Repeat the calculations assuming the simplified diode (silicon) model. (b) Draw the circuit diagram of full wave rectifier having two diodes and explain its operation. [8+8]
5. (a) Compare and contrast FET and BJT. (b) Give the constructional features of JFET and explain its operation with the help of the drain characteristics. (c) From the drain characteristics derive mutual characteristic and explain the shape of the curve qualitatively. [6+6+4]
6. (a) Draw the circuit of a current shunt feedback amplifier and explain. (b) An amplifier has a gain of 10,000 without feedback. The gain is reduced to 50 with negative feedback. Find the feedback factor. (c) Explain the principle of operations of Tuned amplifiers.
7. (a) Draw the circuit diagram of Wien bridge oscillator using BJT. Show that the gain of the amplifier must be at least 3 for the oscillations to occur. (b) For the fixed-bias Ge transistor, n-p-n type, the junction voltages at saturation and cutoff one in active region, may be assumed to zero. This circuit operate properly over the temperature range -50 oC to 75 oC and to just start malfunctioning at these extremes. The various circuit specifications are: VCC = 4.5V, VBB = 3volts, hfe=40 at -50 oC, and hfe=60 at 75 oC, ICBO = 4 μA at 25 oC and doubles every 10 oC. Collector current is 10 μA. Design the values of Rc1, R1 and R2. [8+8]
8. (a) Explain how a shift register is used as a Ring counter. Draw the O/P waveformfrom each flip-flop of a 3-stage unit. (b) Prove that if w′x + yz = 0, then wx + y′ (w′+z′) = wx + xz + x′z′ + w′y′z. (c) Represent the given negative numbers in sign-magnetude, 1’S and 2’S com- plement representation in 12-bit format. i. –64 ii. –512.
SET :4
1. Consider a general A.C circuit in which the current leads the applied voltage by an angle φ. Write the equation for the voltage and current and hence derive the equation for the power. Also plot the voltage, current and power wave forms. [16]
2. (a) Why is the core of the transformer laminated? (b) What are the various losses in a transformer? And how do these losses vary? (c) A single phase 50 Hz transformer has 100 turns on the primary and 400 turns on the secondary. The cross sectional area of the core is 250 cm2. The primary winding is connected to 230 Volts. Determine i. E.M.F induced in the secondary winding. ii. The maximum value of the flux density in the core. [4+8+4]
3. (a) Draw the V-I characteristics of p-n diode and explain. (b) i. What is the current in the diode shown in the figure
3(b)i ii. Calculate the load voltage, load power, diode power and total power in the above circuit. (c) Explain how p-n junction diode act as a rectifier.
4. (a) The half wave rectifier shown in the figure 4a is fed with a sinusoidal voltage V=20 sin100t. i. Sketch the output waveform. ii. Determine the DC output voltage assuming ideal diode behaviour. iii. Repeat the calculations assuming the simplified diode (silicon) model. (b) Draw the circuit diagram of full wave rectifier having two diodes and explain its operation.
5. (a) Give the equivalent circuit of UJT and explain its operation with the aid of equivalent circuit. What is intrinsic stand off ratio? Explain its significance.
(b) A transistor with β = 100 is used in CE configuration with collector to base bias. If Rc = 1K , Vcc = 10 V, VBE=0 V and VCE = 4 V. Find the value of RB and stability factor S.
6. (a) List out different distortions that occur in amplifiers and discuss.
(b) Enumerate the effect of negative feedback on the various characteristics of the amplifier.
(c) Draw the circuit diagram of an emitter follower circuit and mention what type of feedback is employed? Justify your answer.
7. Define the following terms with reference to OP-AMPs:
(a) i/p bias current
(b) i/p offset current
(c) open loop gain
(d) i/p off set voltage
(e) o/p offset voltage
(f) CMRR
(g) PSSR
(h) Skew rate.
8. (a) Realize Exclusive OR gate using minimum number of NAND gates.
(b) Realize SR flip-flop using NAND gates.
(c) Explain the principle of decade counter and realize it using JK-flip-flops.
(d) Realize exclusive OR gate using basic gates
VAB in the circuit shown in the figure 1a Figure 1a (b) Find the power dissipated in 40 ohm resistor of figure 1b shown. [10+6] Figure 1b
2. (a) Derive the torque equation of a D.C motor. (b) A 4-pole wave wound D.C armature has 294 conductors. Find i. Flux per pole to generate 230 V at 1500 r.p.m. ii. Electromagnetic torque at this flux when armature current is 120 A.[8+8]
3. (a) Determine the range of input voltage that maintains an output voltage of 10 V at the output for the regulator shown in the figure 3a Figure 3a (b) Explain the applications of Zener diode. (c) Explain static and Dynamic Resistance of a diode. [4+8+4]
4. (a) The half wave rectifier shown in the figure 4a is fed with a sinusoidal voltage V=20 sin100t. i. Sketch the output waveform. ii. Determine the DC output voltage assuming ideal diode behaviour. iii. Repeat the calculations assuming the simplified diode (silicon) model. Figure 4a (b) Draw the circuit diagram of full wave rectifier having two diodes and explain its operation. [8+8]
5. (a) Sketch a family of drain and mutual characteristics and explain the shape of the curves qualitatively for a JFET. (b) For a source self-bias circuit if ID = 0.8 mA, IDSS = 1.65 mA and VP = –2V find VGS. [8+8]
6. (a) With the help of block diagrams, explain the four different feed back topologies. (b) Draw the circuit of a voltage series feedback amplifier with BJT. What is the effect of this feedback as Ri and R0. [6+10]
7. (a) Explain the operation of an integrator using OP-AMPs. (b) Distinguish between positive and negative feedbacks. (c) List out the characteristics of OP-AMP. [6+4+6]
8. (a) Realize Full-adder using logic gates. (b) Explain the principle of operation of D to A converter. (c) Simplify the following functions i. A′BC′ + A′C′D + A′B′D′ + AC + BCD′ ii. A′B′D′ + A′CD + A′BC.
SET :2
1. With a neat sketch explain the construction and working principle of moving iron (M.I) type instrument. Write down the torque equation. [16]
2. (a) Does the induction motor have any similarities with the transformer. Compare the similarities and differences between them. (b) A 20 h.p, 400 V, 50 Hz, 3-phase induction motor has an efficiency of 80% and working at 0.7 p.f. The motor is connected to 400 Volts, 3-phase supply calculate the current drawn by the motor from the mains. [8+8]
3. (a) For the network shown in the figure 3(a)i determine the range of RL and IL that will result in VRL being maintained at 10 V. i. Determine the maximum Wattage rating of the diode. Figure 3(a)i ii. The reverse saturation current of the diode is 1 μA. Its peak inverse Voltage is 500V. Find ri, Vo that PIV is not exceeded. show in figure 3(a)ii & figure 3(a)iii Figure 3(a)ii Figure 3(a)iii
4. (a) A sinusoidal voltage of peak value 40V and frequency 50 Hz is applied to HWR using PN diode. The total load resistor is 800 . Neglecting cut in voltage and using idealized characteristic for the diode with Rf=8 and Rr=α calculate i. Peak D.C and RMS values of load current ii. D.C and A.C output power iii. Rectifier efficiency iv. Ripple factor. (b) Derive the formulas used in the above problem. [8+8]
5. (a) Draw the static drain characteristics and transfer characteristics of an N- channel MOSFET and explain the shape of the curves qualitatively. (b) Explain the following i. BJT Switching times with suitable sketches. ii. Early effect and its consequences. [6+10]
6. (a) Classify and define the amplifiers depending on the conduction period and sketch the input and output waveforms. (b) Show that the maximum theoretical efficiency of a class A power amplifier is 50%. [8+8]
7. (a) Find the resistance R and hfe for the transistor to provide a resonating frequency of 5 kHz of a transistorized phase shift oscillator. The biasing resistances are 25 kand 47 k. The load resistance is 10. The capacitor in the tank circuit is 1000 pF which hie of the transistor is 2 k. (b) Explain the role of commutating capacitors in multivibrator circuits. (c) Design an Astable multivibrator circuit with 50% duty cycle and f=2 KHz, VCC=10V, VBE(Sat) = 0.6V, VCE(Sat) = 0.3V. Using N-P-N Si transistors. [6+2+8]
8. (a) Explain with a block diagram the major blocks of a digital computer. (b) Implement the following with either NAND or NOR gates. Use only 4 gates only the normal inputs are available. F = w′xz + w′yz + x′yz′ + wxy′z. (c) With a circuit diagram, explain Counter type A to D converter. [4+6+6]
SET :3
1. (a) Define resistance. (b) State and explain Ohms Law. (c) Find out the equivalent resistance of the following circuit between the points A and B (all values are in ohms) as shown in the figure 1c [2+4+4] (d) Find the impedance between ‘X’ and ‘Y’ points of the figure 1d shown.
2. (a) Give the constructional features of “CORE” and “Shell” types of transformers, and give the advantages and disadvantages of each type. (b) A 5 KVA, 2300 / 230 V, 50 Hz transformer was tested for the iron loss with normal excitation and copper losses at full load, and these were found to be 40 Watts and 112 Watts respectively. Calculate efficiency of the transformer at i. full load. ii. half full load. Assume the power factor of the load as 0.8. [8+8]
3. (a) Draw the equivalent circuits of i. ideal diode ii. Simplified model of diode. iii. piece wise linear model of diode. Draw their characteristics. (b) Derive the expression for diffusion capacitance in a diode. [10+6]
4. (a) The half wave rectifier shown in the figure 4a is fed with a sinusoidal voltage V=20 sin100t. i. Sketch the output waveform. ii. Determine the DC output voltage assuming ideal diode behaviour. iii. Repeat the calculations assuming the simplified diode (silicon) model. (b) Draw the circuit diagram of full wave rectifier having two diodes and explain its operation. [8+8]
5. (a) Compare and contrast FET and BJT. (b) Give the constructional features of JFET and explain its operation with the help of the drain characteristics. (c) From the drain characteristics derive mutual characteristic and explain the shape of the curve qualitatively. [6+6+4]
6. (a) Draw the circuit of a current shunt feedback amplifier and explain. (b) An amplifier has a gain of 10,000 without feedback. The gain is reduced to 50 with negative feedback. Find the feedback factor. (c) Explain the principle of operations of Tuned amplifiers.
7. (a) Draw the circuit diagram of Wien bridge oscillator using BJT. Show that the gain of the amplifier must be at least 3 for the oscillations to occur. (b) For the fixed-bias Ge transistor, n-p-n type, the junction voltages at saturation and cutoff one in active region, may be assumed to zero. This circuit operate properly over the temperature range -50 oC to 75 oC and to just start malfunctioning at these extremes. The various circuit specifications are: VCC = 4.5V, VBB = 3volts, hfe=40 at -50 oC, and hfe=60 at 75 oC, ICBO = 4 μA at 25 oC and doubles every 10 oC. Collector current is 10 μA. Design the values of Rc1, R1 and R2. [8+8]
8. (a) Explain how a shift register is used as a Ring counter. Draw the O/P waveformfrom each flip-flop of a 3-stage unit. (b) Prove that if w′x + yz = 0, then wx + y′ (w′+z′) = wx + xz + x′z′ + w′y′z. (c) Represent the given negative numbers in sign-magnetude, 1’S and 2’S com- plement representation in 12-bit format. i. –64 ii. –512.
SET :4
1. Consider a general A.C circuit in which the current leads the applied voltage by an angle φ. Write the equation for the voltage and current and hence derive the equation for the power. Also plot the voltage, current and power wave forms. [16]
2. (a) Why is the core of the transformer laminated? (b) What are the various losses in a transformer? And how do these losses vary? (c) A single phase 50 Hz transformer has 100 turns on the primary and 400 turns on the secondary. The cross sectional area of the core is 250 cm2. The primary winding is connected to 230 Volts. Determine i. E.M.F induced in the secondary winding. ii. The maximum value of the flux density in the core. [4+8+4]
3. (a) Draw the V-I characteristics of p-n diode and explain. (b) i. What is the current in the diode shown in the figure
3(b)i ii. Calculate the load voltage, load power, diode power and total power in the above circuit. (c) Explain how p-n junction diode act as a rectifier.
4. (a) The half wave rectifier shown in the figure 4a is fed with a sinusoidal voltage V=20 sin100t. i. Sketch the output waveform. ii. Determine the DC output voltage assuming ideal diode behaviour. iii. Repeat the calculations assuming the simplified diode (silicon) model. (b) Draw the circuit diagram of full wave rectifier having two diodes and explain its operation.
5. (a) Give the equivalent circuit of UJT and explain its operation with the aid of equivalent circuit. What is intrinsic stand off ratio? Explain its significance.
(b) A transistor with β = 100 is used in CE configuration with collector to base bias. If Rc = 1K , Vcc = 10 V, VBE=0 V and VCE = 4 V. Find the value of RB and stability factor S.
6. (a) List out different distortions that occur in amplifiers and discuss.
(b) Enumerate the effect of negative feedback on the various characteristics of the amplifier.
(c) Draw the circuit diagram of an emitter follower circuit and mention what type of feedback is employed? Justify your answer.
7. Define the following terms with reference to OP-AMPs:
(a) i/p bias current
(b) i/p offset current
(c) open loop gain
(d) i/p off set voltage
(e) o/p offset voltage
(f) CMRR
(g) PSSR
(h) Skew rate.
8. (a) Realize Exclusive OR gate using minimum number of NAND gates.
(b) Realize SR flip-flop using NAND gates.
(c) Explain the principle of decade counter and realize it using JK-flip-flops.
(d) Realize exclusive OR gate using basic gates
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