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(192039 Pages:2

configuration using hybrid 7 equivalent circuit.

What is a cascode amplifier? Draw the circuit diagram and derive an expression
for mid band voltage gain of cascode amplifier.

An amplifier without feedback has a voltage gain of 50, input impedance 1kQ and
output impedance 2.5kQ. Obtain the input and output impedances of current-shunt
negative feedback amplifier using the above amplifier with a feedback factor of
0.2.

Draw the circuit diagram of a Wien bridge oscillator. Explain how Barkhausen
criterion for oscillation is satisfied by the circuit and derive an expression for the
frequency of oscillation.

Differentiate between synchronous and stagger tuned amplifiers.

Draw the circuit diagram of a Colpitts oscillator

PART C
Answer any two full questions, each carries20 marks.

Classify power amplifiers based on collector current waveforms and conduction
angle.

Draw the circuit diagram of class A series fed power amplifier and prove that the
conversion efficiency is 50% by using transformer coupling.

What is cross over distortion in class B power amplifier? How is it avoided?

Draw the circuit diagram of bootstrap sweep circuit.

Explain the working of an astable multivibrator with necessary base and collector
waveforms.

Derive an expression for the free running frequency of astable multivibrator.

With a neat circuit diagram explain the working of a transistor based shunt voltage
regulator.

How is short circuit protection provided in series voltage regulator.

Analyze a common source amplifier with source resistance bypassed and derive
expressions for input impedance, output impedance and voltage gain using small

signal equivalent circuit..

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