B3D157S Pages: 2

OR

. a. Draw the circuit of a RC phase shift oscillator and design the circuit for an output frequency
of 10KHz. (7)
b. Draw the circuit of a tuned amplifier and explain the working. (4)
c. Draw the feedback amplifier topologies clearly indicating the currents, voltages, transfer
gain and feedback factor. (4)

PART C
Question No. 7 is compulsory.

. a Draw the circuit diagram of collector coupled astable multivibrator and explain its operation

with neat waveforms (10)
b. Draw the circuit of a series voltage regulator with error amplifier and explain the working

(6)
c. Suggest one scheme to incorporate short circuit protection in a series regulator (4)
a. Show the maximum efficiency of a class B power amplifier is 78.5%. (5)
b. What is crossover distortion? How it can be eliminated? (3)
c. Draw the circuit of a class AB power amplifier and explain the working. (6)
d. Draw the circuit of a Schmitt trigger and explain the working (6)

OR

. 9. Design a series voltage regulator with error amplifier having the following specification
Output voltage-5 voltsMaximum load current -100mA Input voltage range 7 — 12 volts

(Make suitable assumptions) (10)
b. With the help of low frequency and high frequency equivalent circuit derive the expression
for voltage gain at low and high frequencies (10)

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