Discrete Electronic Circuits - Dec 2015

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.

Solve any Four questions.

1 (a) Draw output waveform for following circuits. (5 marks) 1 (b) Explain Wilson current source.(5 marks) 1 (c) What are different biasing methods used for FET, explain self bias techniques.(5 marks) 1 (d) State and Explain Barkhausen criteria.(5 marks) 1 (e) Derive expression for efficiency for Class A transformer coupled amplifier.(5 marks) 2 (a) Find Icq, Vceq, Ri and R0 for following circuit with RC=1.2 kΩ. (10 marks) 2 (b) Explain any one method for biasing for E-MOSFET.(10 marks) 3 (a) Find Av, Ri and R0 for following circuit. (10 marks) 3 (b) Explain need for cascading of amplifiers. Explain CS-CE combination in detail.(10 marks) 4 (a) What is use of negative feedback in amplifier? Draw block diagram for current shunt feedback and Af, Rif and R0f.(10 marks) 4 (b) Explain High frequency response of CS-CS amplifier and hence derive equation of output frequency.(10 marks) 5 (a) For the following diff-amp find Ad, Ac and CMRR. (10 marks) 5 (b) Explain working of Class B push-pull power amplifier. What it cross over distortion?(10 marks)

Write short notes on (any four).

6 (a) High frequency oscillator(5 marks) 6 (b) Cascode amplifier(5 marks) 6 (c) High frequency model for BJT(5 marks) 6 (d) Heat sinks(5 marks) 6 (e) Constant current source used in diff-amp.(5 marks)