൭

a)

b)

D7265

Explain Miller’s theorem.

Discuss the variation of input and output resistance on voltage series and current

shunt feedback.

Draw the circuit of a cascode amplifier and briefly explain its features.

Explain the working of an astable multivibrator circuit with a neat circuit diagram

PART C
Answer any two full questions, each carries 20 marks.

and waveforms. Derive an expression for period of oscillation.

For the circuit shown, Ipss= 5൩൧, gmo = 2500൮5. If Rs = 82042, what is Ip, Ves

and Vps.

For a series fed class A amplifier, Rg 511९, Rc =20Q and Vcc = 20V. 8 for BJT is
25. Calculate the input power, output power and conversion efficiency for an input

ഹ്‌ GND

voltage resulting in a base current of 10mA peak.

Derive expressions for voltage gain and output resistance for a common source
amplifier with source bypassed using small signal model in mid frequency.

Compare Class A, Class B and Class AB power amplifiers.

Explain the working of bootstrap circuit with a neat circuit diagram and waveforms.

Prove that the conversion efficiency of Class B amplifier is 78.5%.

With a neat circuit diagram, explain how output voltage can be regulated by using
series feedback voltage regulator. How short circuit protection can be implemented

in this?

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