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Reg No.:_. Name:

APJ ABDUL KALAM TECHNOLOGICAL UNIVERSITY
THIRD SEMESTER B.TECH DEGREE EXAMINATION, MAY 2019
Course Code: CS207
Course Name: ELECTRONIC DEVICES AND CIRCUITS

Max. Marks: 100 Duration: 3 Hours
PARTA
Answer all questions, each carries 3 marks. Marks
1 Derive the input- output relationship of an RC integrator circuit. (3)
2 Draw and explain the circuit of a 78XX IC based voltage regulator. (3)
3 Design a loaded 5.1 V zener diode voltage regulator for a load current of 20mA. (3)

Input voltage is 12 V dc. Assume that zener knee current is 5 mA.
4 Distinguish between (3)
(1) Series and Shunt Clippers
(ii) Positive and Negative Clippers
PART B
Answer any two full questions, each carries 9 marks.
5 9) Draw and explain the circuit of a voltage doubler. (3)
0) With the help of characteristic curves, explain the principle of operation of a (6)
Junction Field Effect Transistor. Mark its regions of operation on the curve.
6 9) Draw and explain the transistorised sweep circuit using a normally off transistor (4)
switch.
b) Draw and explain the circuit of a series voltage regulator. (5)

7 ഒ) Design circuits using passive components to perform the following waveform (4)

conversions:
(1) 2 KHz triangular wave to square wave
(ii) 0.5 KHz square wave to triangular wave
b) Draw and explain the block diagram of SMPS. (5)
PART C
Answer all questions, each carries 3 marks.
8 Explain thermal runaway in transistors. (3)
9 Draw the circuit of a monostable multivibrator using transistors. (3)
10 Compare BJT and FET. (3)
11 State and explain Barkhausen Criteria. (3)

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