Jadavpur University 2007 B.E Mechanical Engineering ELECTRONICS - exam paper

Ex/ML 21F/24/2006
INTER ENGG. ( MECHANICAL ) EXAMINATION, 2006
( first Semester )
ELECTRONICS
Time: 3 hours Full Marks : 100
( 50 marks for every part)
Use a separate answer-script for every part.
PART—I
ans any 5 ques..
1. (a) discuss intrinsic, n-type and p-type semiconductor.
(b) explain the expression for the current due to drift
and diffusion. 6+4
2. With the help of energy-band diagrams discuss the
difference ranging from insulator, semiconductor and metal.
Mention the order of resistivites with examples. 10
3. What is specification of a PN junction diode ? discuss
its V-I characteristics. How junction capacitance is
formed ? Mention its order of values. 10
4. With the help a circuits diagram discuss the working
of full wave rectifier circuit. obtain out the expression
of ripple voltage using capacitor filter. 10
[ Turn over
( two )
5 How a Zener diode is used to get the output voltage
stable ? Why you need to know the specification of
the diode ? Mention a few order of values available in
the market. 10
6. With the help of 1 Q-point stable circuit, discuss
the requirement of such circuit considering collector
current Io, leakage current Ico and base current IB.
Mention the order of values of amplification factor of
the transistor. 10
7. explain the biasing of NPN and PNP Transistors and
V-I characteristics of a CE amplifier. discuss how
amplification of the input signal is achieved showing
saturation, active and cut-off regions. 10
8. explain ,the advantages, of feedback amplifier and obtain
out the condition of 1 oscillator. What, is phase
shift ranging from input and output of 1 amplifier?
discuss the phase shift oscillator circuit mentioning
the phase matching in the input. 10
PART-II
ans any 5 .questions.
9. A majority gate is a digital circuit whose output is
equal to the majority of the inputs, are 1's. The
output is '0' otherwise. By means of a truth table obtain
the Boolean function for a 3-input majority gate.
find the minterm representation of the function
also. 10
( three )
10. Prove that
AB+ BC + AC = AB+ BC. 10
11. Simplify the subsequent function K-map.
F ( A, B, C, D ) = S ( 0, 6, 8, 13, 14 ) + S d ( 2, 4, 10 ).
10
12. Implement the subsequent function in 2 levels using
(a) only NAND gates
(b) only NOR gates.
f = A (B+C). 5+5
13. What is a multiplexer ? Draw the block diagram of a
2n line to one line multiplexer. Implement the subsequent
function using multiplexer :
F ( A, B, C ) = S ( one 2, 4, five ). 2+2+6
14. A combinational circuit is described by the subsequent
three functions:
Design the circuit with a single decoder and minimum
number of SSI gates. 10
15. What is a full adder ? find the logic functions for
full adder and implement, it using 2 half adders.
2+4+4

Earning:   Approval pending.