Question Paper: Discrete Electronic Circuits : Question Paper Dec 2013 - Electronics Engineering (Semester 4) | Mumbai University (MU)
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## Discrete Electronic Circuits - Dec 2013

### Electronics Engineering (Semester 4)

TOTAL MARKS: 80
TOTAL TIME: 3 HOURS
(1) Question 1 is compulsory.
(2) Attempt any three from the remaining questions.
(3) Assume data if required.
(4) Figures to the right indicate full marks.
1 Design a two stage RC coupled amplifier for following requirements:
FL = 20Hz.Av ≥ 2000
SIco = 9
Vo = 3V
Select transistor from the table at the end of question paper.
(20 marks)
2 (a) Explain the procedure to find lower cut-off frequency for CS amplifier and hence find the lower cut-off frequency for the given circuit. (10 marks) 2 (b) Explain Wien Bridge oscillator and hence derive equation of frequency also state the use of it. (10 marks) 3 (a) Explain High frequency response of CE Amplifier and state the limitations of CE amplifier.(10 marks) 3 (b) Design RC phase shift oscillator to generate frequency of 10KHz.(10 marks) 4 (a) Design class A power amplifier for car music system to give output power of 20W to a load of 8Ω. (10 marks) 4 (b) For the given circuit find Avf, Rif and Rof. (10 marks) 5 (a) For the single input balanced output differential amplifier calculate:
(i) Q point
(iii) Ri and
(iv) Ro
Assume βac=βdc=100 for both transistors.
(10 marks)
5 (b) Explain operation of Class B push-pull amplifier and derive equation for power efficiency. (10 marks) 6 (a) Draw block diagram of each type of negative feedback amplifier with equation of gain, feedback factor, input impedance and output impedance.(10 marks) 6 (b) Explain any two types of current sources that can be used with differential amplifier.(10 marks)

### Write short notes on any four:-

7 (a) Hartley oscillator.(5 marks) 7 (b) Class C power amplifier with applications.(5 marks) 7 (c) Use of RE? in differential amplifier (swamping resistor).(5 marks) 7 (d) Analysis of voltage shunt feedback amplifier. (5 marks) 7 (e) Darlington amplifier with applications. (5 marks)