Punjab State Board of Technical Education and Industrial Training 2009 Diploma Electronics and Communication Electronic devices and circuits - Question Paper

part A


1. Fill in the blanks [15]

a. The gain of amplifier is 40.It is equal to ___________ decibels.
b.___________configuaration is best suited for cascading amplifiers.(common emitter, common collector)
c.Transformer coupled multistage amplifier is used for amplifying __________ frequency signals.
d.At cutoff frequency gain drops to ________% fo maximum gain .
e.Barkhausen criterion for producing oscillation is _________
Low pass RC circuit will act as integrtor if _________
g.Negative feedback in an amplifier increases/decreases the input impedance.
h. IC 7812 is used for ________.
i. CMRR is described as _________
j. Photo diode operates under ______biased condition


part B [5*6]

2.
i. What is the need of coupled stages?What are requirements of the coupling network?

ii.What are the various kinds of distortions in amplifiers?

iii.Discuss the working of Hartely Oscillator.

iv.With the help of circuit diagram discuss the voltae shunt feedback.

v.Discuss the basic principle of working of diode clippers.

vi. discuss line and voltage regulation.

vii. explain the working of operational amplifier as differentiator.




part C [3*10]

3.Discuss the working of TC coupled multistage amplifier.What are its advantages and disadvantages?

4.Derive the expression for gain with feedback. explain in detail the effects of negative feedback.

5.What are the applications of multivibrators?Discuss the working of IC 555 as astable multivibrator.

6.What is the basic principle of working of photo resistor? explain its characteristics.

Earning:   Approval pending.