Download AKTU B-Tech 4th Sem 2015-16 401MTU Electronics Circuits Question Paper

Download AKTU (Dr. A.P.J. Abdul Kalam Technical University (AKTU), formerly Uttar Pradesh Technical University (UPTU) B-Tech 4th Semester (Fourth Semester) 2015-16 401MTU Electronics Circuits Question Paper

Printed Pages: 6 EEC?401/EC-401 (MTU)
(F allowing Paper ID and Roll N 0. to be ?lled in your
Answer Books)
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B.TECH.
Theory Examination (Semester?IV) 2015-16
ELECTRONICS CIRCUITS
Time : 3 Hours Max. Marks : 100
Note : Attempt all Sections.
Section-A
1. This question consist of short answer questions. Attempt
all parts. All parts carry equal marks. (2X10 = 20)
(a) What is Op?amp? Give its equivalent circuit.
(b) For NMOS transistor, write the drain current expression
for all its region.
(0) Draw a high frequency T model of n?channel MOSFET
incorporating output resistance.
(1) P.T.O.

((1) Draw the circuit diagram for CB ampli?er.
(e) Calculate [3 and 0t for a transistor if emitter current is
lOmA and collector current is 9mA.
(f) De?ne input o?set voltage of MOS di?erential pair.
(g) Explain why voltage divider biasing is preferred.
(h) De?ne Unity gain frequency.
(i) Draw a large-signal equivalent circuit model NPN
transistor, incorporating the output resistance.
(j) Give the Barkhausan conditions to obtain sustained
oscillations.
Section-B
2. Attempt any FIVE questions. All questions carry equal
marks. [10X5=50]
(a) (i) De?ne and give the signi?cance of Slew rate and
CMRR. For an op?amp having a slew rate of 60 V/
us, what is the highest frequency at Which a 20V
(2) P.T.O.

(b)
(C)
((1)
(ii)
(ii)
peak to peak sine wave can be produced at the
output?
Describe the characteristics of an Op?amp. Draw
the circuit diagram of difference ampli?er using op-
amp and calculate the di?erential gain (A 01), common
mode gain (Am) and di?erential input resistance (Rid).
Descnbe classi?cation ofoutput stage power ampli?er.
Describe the methods ofbiasing for class AB power
ampli?er.
What do you mean by cross over distortion.
Describe how can it be overcome.
Describe the construction and operation of N?channel
enhancement MOSFET. Describe the role of substrate
(the body effect) in MOSFET.
Draw the high frequency equivalent circuit mo del for the
MO SFET and list all MO SFET internal Capacitances.
(0
Give the circuit for CC ampli?er and calculate Rin
and Rout for the CC ampli?er.
(3) P.T.O.

(f)
(g)
(h)
(ii)
(i)
(11)
(ii)
(ii)
Draw the circuit diagram ofCB ampli?er and calculate
expression for short?circuit current gain With T?model.
Discuss the various internal capacitances for BJT. A
particular small geometry B] T has fr 0f5 GHz and Cu
= lpF When opertated at IC = 0.5mA. What is CT: in
this situation?A1s0 ?nd gm. For [3 = 150, ?nd r7E and fB
Draw the circuit diagram of a Wien-bridge oscillator
and derive an expression for the frequency of
oscillations.
Explain the operation ofMOS differential pair with
di?erential input voltage. Also calculate the range of
input differential signals.
For the active loaded BJ T differential ampli?er let
I: 0.8mA, VA = 100V and B = 160. Find Gm, R0,Adl
and Rid.
Design a series ? shunt feedback ampli?er and derive
expresswns for Af , R0f and RH.
For the Colpitt?s oscillator, derive an expression for
the frequency ofoscillation.
(4) P.T.O.

Section-C
Attempt any TWO questions. Each question carry equal marks.
3. (a)
(b)
4. (a)
(b)
5. (a)
(15x2=30)
Explain the effect of ?nite open loop gain and bandwidth
on the circuit performance. Calculate the frequency
response of closed loop inverting ampli?er.
Explain the working of BJT as an ampli?er and as a
switch with the help of neat diagram and necessary
equations.Als0 calculate the ampli?er gain.
Discuss 21 common- source ampli?er, draw its ac
equivalent circuit and obtain expression for its
terminal characteristics.
Describe the operation of class B push?pull power
ampli?er giving its circuit, also obtain its ef?ciency.
Draw the NMOS differential ampli?er with a common-
mode input signal and calculate the common Mode Gain
and CMRR. Also explain the effect of RD mismatch 0n
CMRR.
(5) PIX)

(b) Explain the merits and demerits of negative feedback.
Also explain in bn'ef the various topologies used in negative
feedback.
(6) P.T.O.