Download AKTU B-Tech 4th Sem 2015-16 NEC 402 Electronic 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 NEC 402 Electronic Circuits Question Paper

Printed Pages: 4 NEC-402
? (Following Paper ID and Roll No. to be ?lled In your
Answer Books)
RollNoJITlll1lll
BEECH.
Theory Examination (Semester-IV) 2015-16
? ELECTRONIC CIRCUITS
lime : 3 Hours Max. Marks .- 100
Sec?on-A
Q1. Attempt all parts. All parts carry equal marks.
(10XZ-=20)
(a) What do you mean by voltage follower circuit ? explain
in brief.
(b) Why Op Amp is rarely used in open loop con?gtna?on?
(c) What is Barkhausen criteria for sinusoidal oscillations
(d) Draw the current mirror circuit and write its output cur-
rent equation.
(e) State the properties of negative feedback.
(f) What are the advantages of using an active load in
di??ential ampli?er circuit?
(3) What are the types of feedback ?
(1) P.T.O.
806/335/291/7275

(h) Draw the Small signal Tl: Model of BJT.
(i) How does the slew rate effects Finite or Full power
Band Width of Op Amp ?
(1) An enhancement type NMOS transistor with V? = 0.7V
? has its source terminal grounded and a 1.5V dc applied
to the gate. In what region does the device operate for
VD = 0.9V.
Section-B
Q2. Attempt any ?ve questions from this section. (lOXS-SO)
(a) Discuss the effect of ?nite loop gain on the perfonnance
of non-invem'ng OP-AMP.
(b) A MOSFET is to operate at ID=. lmA and is to have
gm=1 mA/V. If Kn=50uAlV2. Find the required W/L
ratio and the overdrive voltage.
(c) Draw the high ??equency model of MOSFET and drive
an expression of fH.
(d) BJT transistor ampli?er stage has RE=RC=1.5kQ,
Rs =6000Q, RL =2kQ and transistor parameter as
B=100 and rn=1kQ Determine the value of CC], CC;
and CE needed to obtain fL=50Hz and also draw the
circuit.
(e) Explain the operation of BJT as a switch and as an
ampli?er.
(2)
80655309117275
(1) Explain the Nonideal characteristics of MOS differ-
ential pair.
(g) Draw a circuit diagram of Wein bridge oscillator and
drive an expression of frequency of oscillation.
Calculate the ?'equency of oscillation for given values of
R1=R2=200KQ, C1=C2=200pE
(h) Design the circuit shown in ?g.1 so that transistor operr
ates at ID = 0.4mA and VD= +0.5V. The NMOS tran-
sistor has V,=0.7V. pnCox = lOOpA/Vz, L = 1m and
W = 32 pm. Neglect the channel length modulation.
Vnp = +2.5V
L - Vs: = 4.5V
t Fig. 1
Section-C
Note: Attempt any two questions from this section. (15x2=3o)
Q3. (a) Draw Instrumentation Ampli?er. How does it improve
the performance parameters of an Op Amp?
(3) P.T.O.
806/538/291/7275

(b)
04- (a)
(b)
05- (a)
(b)
De?ne slew rate and show how it is related to full
power bandwidth. An Op-amp has a rated output
voltage _-+_- 10V and slew of rate of lV/uS. What is its
?Jll power band width.
Consider the common emitter circuit using a BJT
havlng |s*10??A. A collector resistance Rc=6.8 K9
and power supply VCC=10V.
(i) Determine the value of bias voltage VBE required
to operate the transistor at VCE=3.2V .what is the
corresponding value of Ic.
(ii) Find the voltage gain Av at this bias point.
(iii)Ifthe input sine wave of 5mA peakamplitude is
superimposed one V33. Find the amplitude of
output sine wave signal.
Draw the circuit for CB ampli?er and ?nd expression for
short circuit gain.
Draw the T equivalent circuits of common source am-
pli?er with a source ampli?er with a source resistance
and obtain the expressions for Rn, Rum, and Gv.
An inverting ampli?er has feedback resistor R2=500KQ
and Rl=5KQ Find the ampli?er circuit voltage gain,
inth resistance and output resistance. Also ?nd the output
voltage and input current if the input voltage is given as
.1 volts. Assume the OP-AMP to be an ideal one.
(4)
806/553/291/7275