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Max. Marks: 100

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APJ ABDUL KALAM TECHNOLOGICAL UNIVERSITY

Third semester B.Tech examinations (S) September 2020

Course Code: EC205
Course Name: ELECTRONIC CIRCUITS (EC,AE)
PARTA
Answer any two full questions, each carries 15 marks.
Derive an expression for current stability factor of collector to base bias.

Plot the response of high pass RC circuit to symmetrical square wave input of 2V
peak to peak, 20Hz. Given the cut off frequency of filter is 10Hz.

Derive 3-dB frequency of a high pass RC circuit.

Show how an RC circuit can behave as an integrator.

Obtain the input resistance, output resistance and voltage gain of the given circuit
using hybrid pi model. [Given Vec=15V, Rs 5८11९, Ri=22K, Ro=15K, Rc=8K,
1४216, CE=CC=CB=0.01 uF, B=100 and Vpp=0.7V].

vec

कै +} vo

Draw the circuit of a Common collector amplifier and derive the expressions for
voltage gain and input impedance.

What is the need for biasing and illustrate how Q point is fixed on a DC load line.
Determine the stability factor of a fixed bias CE-BJT amplifier with Vec= 12V,
Rc=10K, Rg=5k and 6-0

PART ந
Answer any two full questions, each carries 15 marks.

Explain the working of Wien bridge oscillator. Derive the expression for its

frequency of oscillation.

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Duration: 3 Hours

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