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(100
t). Calculate
![](file:///C:/Users/Wipro/AppData/Local/Temp/msohtmlclip1/01/clip_image002.gif)
(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 50Ω
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 Ω and RB1 = 5k Ω 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.
0 comments:
Post a Comment
North India Campus