Download AKTU B-Tech 4th Sem 2014-15 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) 2014-15 Electronic Circuits Question Paper

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B.Tech.
(SEM. IV) THEORY EXAMINATION, 2014-15
ELECTRONIC CIRCUITS
Time : 3 Hours] [Total Marks : 100
Note: (1) Attempt all questions.
(2) All questions carry equal marks;
1 Attempt any four parts of the following:- 5X4=20
(a) Draw the circuit diagram of difference ampli?er
using OP-AMP and calculate the differential gain
(Ad) and differential input resistance(Rid).
(b) For the circuit in Fig.0) calculate the values of
v], i1,i2,v0, iLand i0. Also calculate the voltage
gain, current gain and power gain.
131406] [ Contd...

(c)
(d)
(e)
Explain how the performance of an OP-AMP is
affected by the open loop gain of an ampli?er.
Explain the effect of ?nite open loop gain and
bandwidth on the cireuit performance. And
calculate the frequency response of closed loop
inverting ampli?er.
An inverting ampli?er with nominal gain of -20V/V
employs an op-amp having a dc gain of 104 and
a unity gain frequency of 106Hz. What is the 3-dB
, frequency f3dB of the closed loop ampli?er? What
is the gain at 0.1 fsdB and at 10f3dB.
(t) (1) Describe the terms Unity- gain Bandwidth
and Full-power Bandwidth.
(ii) For an op-amp having a slew rate of
60 V/ps, what is the highest frequency at
which a ZO-V peak to peak sine wave can
be produced at the output.
2 Attempt any four parts of the following:? 5X4=20)
(a) Den've the id'ch relationship for NMOS working
in saturation region.
131406] 2 I Contd...
(b)
(C)
(1)
(ii)
(Iii)
(M
131406]
Explain the need of biasing. Also explain the
merits and demerits of the various biasing
techniques used? in MOSFET.
Consider the FET ampli?er of Fi g.(2) for the case
Vt=2V, kn'(W/L)=1mA/V1, VGS?nw. VDD= 10v
and RD=3.6KQ?
- d I.)
ll) 4?
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II;
?0?,
'06:
vcs-T- _, 21;
Fig.(2)
Find the dc quantities ID and VD,
Calculate the value of gm at the bias point.
Calculate the value of voltage gain.
If the MOSFET has xzooow?l, ?nd r0 at the
bias point and calcfilate the voltage gain.
3 | Contd...

(d) Calculate the MOSFET Unity ?Gain Frequency
(FT) with the help of MOSFET high frequency
model. 7
(e) In the circuit of?Fig.(3) let RG=10MQ,
RD=10KQ, and VDD =10V. Find the value
of VD and VG for VL=1V and
kn' (W/L)=O.5m A/V2
pr
RD
I
as +0
Fig. (3)
(0 Calculate the overall gain 0?. = Vo/Vsig? input
resistance and output resistance for a Common
Source Ampli?er.
131406] 4 [ Contd...
3
Attempt any-two parts of the following:
(a)
(b)
(9)
ampli?er.
??5 5 I e\
Explai?r?t'the working of BJT as an ampli?er and
as' a" switch with the help of neat diagram and
necessary equations. Also calwlate the ampli?er
gam
Calculate the voltage gain for the circuit given in
Fig.(4). AssumeB =100.
'Vct: ' 2?40 V'
mgm-
Explain the effect of eech capacitor Of a CB
ampli?er with the gatai?frequency curve. A130
discuss the 710w frequency response of "a CE
? t
10X2=20