## Electronic Circuits and Devices Question Paper of 3rd Semester ECE16 Download Previous Years Question Paper 2

• Friday, September 09, 2016

Roll No.
Total No. of Questions : 091
B.Tech. (Sem. - 3'd)
ELECTRONICS DEVICES & CIRCUITS
SUBJECT CODE : EC - 201
Paper ID : [A0301]
Time : 03 Hours
Instruction to Candidates:
1) Section - A is Compulsory.
2) Attempt any Four questions from Section - B.
3) Attempt any Two questions from Section - C.

Section - A
Q1)

a) State what do you understand barrier potential across PN junction and also explain its                          significance.

b) Why bridge type rectifier is preferred over a center tap rectifier?

c) How a PN junction posses a capacitance?

d) What do you understand by the collector reverse saturation current?

e) Why an ordinary junction transistor is called bipolar?

f) What is the need of biasing in a transistor?

g) Draw the h-parameter equivalent circuit of,a transistor.

h) What are characteristics of a good amplifier?

i) In what respect FETs better than BJTs?

j) Define all important parameters of JFET.

Section-B

Q2) The load resistance of a centre tapped full wave rectifier is 500fJ and the
necessary voltage is 60 sin(100t). Calculate
(a) peak, average and rms value of current.
(b) ripple factor and
(c) efficiency of the rectifier.
Each diode has an idealized V-I characteristic having slope corresponding to a resistance of 50â„¦

Q3) Explain how stabilization of operating point is achieved using potential divider biasing circuit.

Q4) Draw the output characteristics of JFET and explain how it works as a voltage controlled device.

Q5) Disuses analysis of transistor amplifier using h-parameter in CB configuration?

Q6) The interbase resistance for a silicon UJT is 8k â„¦ and RB1 = 5k â„¦ with IE = 0.

Determine

(a) Rs2 and (b) intrinsic stand-off ratio.

Determine UJT current, stand-off voltage and peak point voltage when a voltage of 15V is applied between the bases. Take VB = 0.7V.

Section - C

Q7) (a) Draw and explain the drain and transfer characteristics of an n-channel
enhancement MOSFET.

(b) Sketch the circuit of a CS amplifier. Derive the expression for the voltage
gain at low frequencies.

Q8) Define h-parameters. Derive expression for

(a) Voltage gain

(b) Current gain

(c) Input resistance

(d) Output resistance of CE amplifiers using h-parameters.

Q9) Write short notes on two of the following :

(a) Photransister

(b) FET as an amplifier

(c) Miller's theorem.