Anna University Chennai 2003 B.E Electronic Instrumentation & Control Engineer ec 241 Electronic Circuits-II - Question Paper

B.E./B.Tech. DEGREE EXAMINATION, APRIL/MAY 2003.
Fourth Semester
Electronics and Communication Engineering
EC 241 — ELECTRONIC CIRCUITS — II
Time : 3 hours Maximum : 100 marks
ans ALL ques..
PART A — (10 . two = 20 marks)
1. elaborate the effects of negative feedback on distortion and gain of an
amplifier?
2. What is a negative resistance oscillator?
3. Mention the expression for frequency of oscillations for Colpitts Oscillator and
Hartley Oscillator.
4. Mention the features of crystal oscillator.
5. What is meant by unloaded and loaded Q of tank circuit?
6. Mention the applications of class C tuned amplifier.
7. Draw the typical waveforms at base and collector of a collector coupled astable
multivibrator.
8. elaborate the applications of Schmitt trigger circuit?
9. Draw the circuit diagram of an astable blocking oscillator. (RC controlled)
D 247
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10. Mention the features of Miller sawtooth generator.
PART B — (5 . 16 = 80 marks)
11. (i) Brief the Barkhausen criterion for oscillation in feedback oscillator.
(ii) Draw the circuit diagram of Clapp’s Oscillator and derive the expression
for frequency of oscillations. How frequency stability can be improved in
Clapp’s Oscillator?
12. (a) (i) Draw the circuit diagram of RC phase shift oscillator and discuss
its operation.
(ii) elaborate the advantages and disadvantages of Wien Bridge
Oscillator?
Or
(b) (i) Brief about frequency ranges of RC and LC oscillators.
(ii) With simple diagrams discuss the operation of negative resistance
oscillator using Tunnel diode.
13. (a) discuss with a circuit diagram, the operation of a Double Tuned
amplifier.
Or
(b) (i) Brief the principles of ‘Stagger tuning’.
(ii) discuss the Hazeltine method of neutralization.
14. (a) Draw the circuit diagram of a emitter–coupled monostable multivibrator
and discuss its operation with relevant waveforms.
Or
(b) discuss the unsymmetrical and symmetrical triggering of bistable
multivibrator.
15. (a) Draw the circuit diagram of a monostable transistor blocking oscillator
with emitter timing. discuss its operation with the equivalent circuit
during the pulse formation.
Or
(b) (i) define the response of a high–pass RC circuit for step input,
square–wave input and ramp input.
(ii) With simple diagrams, define the principle of bootstrap circuit.

Earning:   Approval pending.