B. Sc. (VI Semester) Examination
PHYSICS
Paper: PHY-363 (New Course)
Electronics and Communication
Full Marks : 80
Pass Marks : 35%
Time : Three Hours
Note: (i) Answer any five out of eight questions.
(ii) The figures in the margin indicate full marks for the questions.
1. (a) What do you mean by passive and active components of an electronic circuit. Explain with examples. 5
(b) State and prove Thevenin’s theorem. 7
(c) Draw the circuit diagram of a voltage divider circuit. 4
2. (a) Discuss the (I~V) characteristic of a zener diode. How a zener diode is used as a voltage regulator. 8
(b) Draw the circuit diagram of a full wave rectifier circuit and explain its working. What is ripple factor of a rectifier? 8
3. (a) Analyze a common emitter amplifier with h parameters. Express voltage gain and draw the frequency response curve. 12
(b) Draw the load line of a basic transistor amplifier. 4
4. Describe the working of a class-B push-pull
(a) Amplifier (with necessary circuit diagram). 8
(b) Distinguish between class-A, class-B and class-C amplifier. 4
(c) What is a field effect transistor and mention its application. 4
5. (a) State and explain Barkhausen criterion of oscillation. Describe a phase shift (R-c) oscillator with necessary circuit diagram. 2+8= 10
(b) Discuss the function of a differential amplifier. 6
6. (a) Explain the operation of ‘AND’ and ‘OR’ Gate using diode. 6
(b) State and prove Demorgan’s theorem. 6
(d) Describe a half adder circuit. 4
7. (a) Why modulation is necessary in electronic communication? Discuss the theory of amplitude modulation. 3+7 = 10
(b) What is single side band transmission and what is its advantage? Compare amplitude modulation and frequency modulation. 3+3= 6
8. Write short notes on any four: 4x4= 16
(a) Clipping and clamping circuit
(b) K-Maps
(c) Pulse modulation
(d) Transistor biasing
(e) Darlington connection
