Calicut University 2005 B.Sc Computer Science Electronic devices and circuits - Question Paper

c4836

2    C 30821

II.    Answer any three questions out of five, each carrying 4 marks :

1    Draw and explain fullwave and bridge rectifiers,

2    Draw the circuit diagram of a FET amplifier and explain its working.

3    Write notes on LC oscillators with necessary diagram.

5 What is thermal runaway ? How it can be eliminated ?

(3 x 4 = 12 marks)

III.    Answer any on question out of 2 carrying 7 marks

1    Explain the working of a RC phase shift oscillator and derive the expression for frequency of oscillations.

2    What is clamping ? Draw and explain the following clamping circuits,

(a)    Clamper clamping + ve!y t OV.

(b)    Clamper clamping -vely at +3V.

(1x7 = 7 marks)

c 4836    Name......................................

Reg.

SECOND YEAR B.Sc. DEGREE EXAMINATION, MARCH/APRIL 2005

Part IIISubsidiary Paper IELECTRONIC DEVICES AND CIRCUITS (Improvement)

Time : Three Hours    Maximum : 60 Marks

Answer five questions, choosing not more than three from each part.

All questions carry equal marks.

Part A

1.    (a) Brief the theory behind the insulators and conductors.

(b) Describe about the step junction aJd graded junction of a PN junction diode.

2.    (a) Describe about the current distribution in a Bipolar Junction Transistor.

(b) Describe the performance of Zener liiode and Varactor diode.

3.    (a) Describe the small signal model of! BJT.

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4.    (a) Describe the performance of UJT

(b) Explain briefly about transferred electron devices.

Part B

1.    (a) Draw the circuit diagram of a full-wave rectifier with L section filter and explain its operation, (b) Compare the performance of BJT amplifier and FET amplifier.

2.    (a) Draw the hybrid equivalent circuit of a BJT common emitter configuration amplifier, and

(b)    With a circuit diagram, explain the operation of an emitter follower.

3.    (a)    Draw the circuit diagram of a RC phase-shift oscillator and explain its operation.

(b)    Describe the characteristics of negative feedback amplifier.

4.    (a)    Draw the circuit diagram of a class A power amplifier and explain.

(b) With a neat circuit diagram, explain the operation of a bistable multivibrator.

Attachment: calicut-university-2005-b-sc-computer-science-31733-1.jpg calicut-university-2005-b-sc-computer-science-31733-2.jpg

Earning:   Approval pending.