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Reg. No. Name:

APJ ABDUL KALAM TECHNOLOGICAL UNIVERSITY
THIRD SEMESTER B.TECH DEGREE EXAMINATION, JULY 2017
Course Code: EC205
Course Name: ELECTRONIC CIRCUITS (AE, EC)
Max. Marks: 100 Duration: 3 Hours
PARTA
Question No. 1 is compulsory.

1. a. Sketch the response of high pass circuit 1௦ a pulse input if RC/,>>1 and RC/t,<<1 where ‏ہا‎

is the time period of input pulse (3)
b. Explain the concept of DC load line of an amplifier. What is the significance of AC load line
(3)
c. Design an integrator for an input square wave of frequency 1 KHz? (2)
0. Draw the hybrid z small signal low frequency model for CE configuration and derive the
expression for input and output impedances (7)
2. a. What are the factors that affect low and high frequency response of a RC coupled amplifier?
(6)
b. How amplifiers are classified based on the position of operating point (4)
c. What are the major factors that affect the stability of a transistor amplifier and how the
stability factors are defined? (5)
OR
3. a. With a hybrid 7 small signal low frequency equivalent circuit derive the expression for
Current and voltage gain of a CE transistor amplifier. (9)
b. Compare the input and output impedance of CE,CB and CC amplifiers. (3)
c. What is cascade amplifier? (3)
PART B

Question No.4 is compulsory.

4. a. Draw the small signal high frequency hybrid x model of a transistor in Common Emitter

configuration and derive the expression for short-circuit current gain. (7)
b. What is Barkhausen criterion for sustained oscillations? (2)
c. Derive the expression for frequency and gain of a Wein bridge oscillator. (6)
5. a. Draw the circuit of a typical cascode connection and explain its main features. (8)
0. Draw the short circuit current gain versus frequency plot on a log scale and mark 1) and fr
on the plot (3)
c. What is meant by short circuit current gain-bandwidth product? (2)
0. What is the significance of gain-bandwidth product? (2)
OR

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