 MORE IN Electronic Devices & Circuits
RGPV Computer Science (Semester 3)
Electronic Devices & Circuits
December 2015
Total marks: --
Total time: --
INSTRUCTIONS
(1) Assume appropriate data and state your reasons
(2) Marks are given to the right of every question
(3) Draw neat diagrams wherever necessary

1(a) What is Zener diode?
2 M
1(b) Why CE configuration is generally used?
2 M
1(c) Explain FET
3 M
Solve any one question from Q.1(d) & Q.1(e)
1(d) The following test results were obtained in a CE amplifier circuit while measuring h-parameters experimentally :
i) With AC output shorted Ib=25μA, Ic=1.2mA, Vbe=30mV and Vce=1.2V
ii) With AC input open circuited Ib=32μ, Vbe=0.3mV and Vce=1.2V
Determine hybrid parameters of the transistor.
7 M
1(e) The collector and bare current of an N-P-N transistor are measured as IC=5mA, IB=50μA and ICBO=1μA
i) Determine α β and IE
ii) Determine new level of IB required to produce IC=10mA.
7 M

2(a) Write down the advantage of negative feedback
2 M
2(b) What is power amplifier?
2 M
2(c) Compare class A, B and C amplifier.
2 M
Solve any one question from Q.2(d) & Q.2(e)
2(d) In a transistor Colpitt's oscillator L=100μF, C2=0.01μF and Cc =10μF, Determine:
i)Operating frequency
ii) Feedback fraction
iii) Minimum gain to sustain oscillations and emitter resistance if RC=2.5k Ω
7 M
2(e) Derive an expression for frequency of oscillation for Wine Bridge Oscillator
7 M

2 M
3(b) What is multivariate? What are their various types?
2 M
Solve any one question from Q.3(d) & Q.3(e)
3(d) Describe darling amplifier and bootstrapping technique in detail with suitable diagram.
7 M
3(e) In the following circuit, VB1=Vid/2,and VB2VB2=Vid/2 where Vid is small signal with zero voltage find the magnitude of different gain 7 M

4(a) What is instrumentation amplifier?
2 M
4(b) Define Slew rate and Offset voltage.
2 M
4(c) Explain OP-amp as differentiated, summer and integrator with suitable diagram.
2 M
Solve any one question from Q.4(d) & Q.4(e)
4(d) Describe Schmitt trigger.
7 M
4(e) Describe 555 timer as a stable vibrator.
7 M

5(a) What do you understand by regulated power supply?
2 M