Instructions:
(a)4 marks will be allotted for correct question and 1 will be
deducted for incorrect question. (b)More than
one answer can be correct.
Que.
1
For a secound order system with the close loop transfer function
T(s)= 9/[s^2+4s+9] the setting time for 2% band in secounds
is
A
1.5
B
2.0
C
3.0
D
4.0
Que.
2
The Nyquist sampling interval,for the signal sinc(700t)+sinc(500t) is
A
1/350 sec
B
(pi)/350 sec
C
1/700 sec
D
(pi)/175 sec
Que.
3
A video transmission system transmitts 625 picture frames/sec. Each frame
consist of a (400*400) pixel grid with 64 intensity levals/pixal.The
data rate of the system is
A
16Mbps
B
100Mbps
C
600Mbps
D
6.4Mbps
Que.
4
Let x and y be two statistically independent random variables uniformly
distributed in the ranges (-1,1)and(-2,1) respectively let Z=x+y, then
the probality that is
A
0
B
1/6
C
1/3
D
1/12
Que.
5
The gain margin and the phase margin of a feedback system with G(s)H(s)=s/(s+100)^3
are
A
0db,0degree
B
infinite,infinite
C
infinite,0degree
D
88.5dB,infinite
Que.
6
For the polynomial P(s)=s^5+s^4+2s^3+2s^2+3s+15,the number of root which
is right halfe of the s-plane is
A
4
B
2
C
3
D
1
Que.
7
Laplace transform of tsin at is
A
2as/[(s^2)+(a^2)]^2
B
2a/[(s^2+a^2)]^2
C
2s/[(s^2)+(a^2)]^2
D
a/[(s^2+a^2)]^2
Que.
8
1Khz sinusoidal signal is ideally sampled at 1500 samples/sec and the
sasmpled signal is passed though an ideal low-pass filter with cutoff
freq. 800hz the output signal has freq.
A
0 hz
B
0.75Khz
C
0.5Khz
D
0.25Khz
Que.
9
A system function has a pole at s=0 and a zero at s=-1 the constant multiplier
is unity for an exitation cos t, the steady state response is given by
A
[(sqrt)2] cos(t+45degree)
B
[(sqrt)2] cos(t-45degree)
C
cos45degree
D
1/[(sqrt)2] cos(t+45degree)
Que.
10
For a liner transfer function of the variable, the transfer function of
the system
A
changes
B
does not change
C
has no relation at all
D
depends on other fectors also
Que.
11
Asignal phase voltage source square wave inverter feeds pure inductive
load.The waveform of the load current will be
A
sinusodal
B
rectangular
C
trapezoidal
D
triangular
Que.
12
The unit ckt of the Nyquist plot transforms into 0dB line of the amplitude
plot the bode digram at
A
0 frequency
B
low frequency
C
high frequency
D
any frequency
Que.
13
An instruction used to set the carry flag in a computer can be classified
as
A
data transfer
B
arithmetic
C
logical
D
program control
Que.
14
a system function H(s)=V(s)/I(s)=s+2/2s+1 the system is at rest
for t<0.i(t)=unit step. the value of v(t) at t=0 and t=infinite respectively
are
A
2 and 1/2
B
1/2 and 2
C
0 and indetermined
D
2 and indetermined
Que.
15
H(s)=V(s)/I(s)=4s+6/s+2, i(t)=unit step function. v(t) as t->infinite
is given by
A
0
B
3
C
4
D
infinite
Que.
16
A driving point impedance Z(s)=V(s)/I(s)=s+1/s+2. the system is initally
at rest for a voltage a signal at unit step, the current i(t) through
Z is given by
A
1-e^-r
B
2-e^-r
C
2-2e^-r
D
1/2e^-r
Que.
17
For the random variable x following the probality density function p(x) shows in fig. the mean and the variance are respectively
^
| P(x)
|
1/4 _____|___________
| | | |
| | |
___|____|___________|_______ x
-1 0 3 ---->
A
1/2 and 2/3
B
1 and 4/3
C
1 and 2/3
D
2 and 4/3
Que.
18
If R is the source resistance the output resistance of an emittor follower
using the s simplified hybrid model would be
A
h(ie)+R(s) /1+h(fe)
B
h(ie) +R(s) /h(fe)
C
R(s) +1/h(fe)
D
1/h(fe)
Que.
19
A unit feedback system has an open-loop transfer function of
G(s)=1000/s(s+10)^2 the magnitude of G(jw) in
the DB at an angular frequency at w= 20 red/sec
A
0dB
B
10dB
C
20dB
D
none of the above
Que.
20
A linear discreate time system has the characteristic equation Z^3-0.81Z=0.the
system
A
is stable
B
is marginally stable
C
is unstable
D
stability can not be assessed from the given information
Que.
21
H(s)=V(s)/I(s) = s+3/(s+3)^2 .i(t) is unit step.V(t)
is steady state is given by
A
3/2
B
3/4
C
1
D
0
Que.
22
In case of synchro error dector,the electrical zreo position of control
transformer is obtained when angular displacement between rotors is
A
0
B
45degree
C
90degree
D
180degree
Que.
23
A second order differential equation is given by
d^2x/dt^2+5dx/dt+7x=7y The undamped natural freq. and damping ratio are
A
1,5
B
5,7
C
1,[(sqrt)7]
D
[(sqrt)7],0.94
Que.
24
An amplifier has a bandwidth of 20khz and a midband gain of 50 without
feedback.If a -ve feedback of 1% is applied.then bandwidth with feedback
is
A
13.3khz
B
30khz
C
10khz
D
40khz
Que.
25
A unity feedback system has the plan transfer function Gp
(s)=1/[(s+1)(2s+1) ] an integral controller with transfer function G
(s)=k/s is placed in the feedforward path the of the feedback system.
the value of k such that the compensated system has an open loop gain
margin of 2.5
A
3/5
B
5/3
C
2
D
none of the above
Que.
26
The fourier transform of the unit step function is
A
f(jw)=j/w
B
f(jw)=jw
C
f(jw)=1/jw
D
f(jw)=1/w
Que.
27
The fourier transform of function f(at) is given by
A
f(at)=aF(w)
B
f(at)=2/a F(w)
C
f(at)=1/a F(w/a)
D
none
Que.
28
The eigen value of the matrix A= |0 1| are
|1 0|
A
1,1
B
-1,-1
C
j,-j
D
1,-1
Que.
29
the trigonometric fourier series ofa perodic function can have only
A
cosine term
B
sine term
C
cosine and sine term
D
none of these
Que.
30
inverse Laplace transform of 10/(s^2)+2s+5 is
A
10 (e^-t) sin2t
B
5 (e^-t) sin2t
C
10 (e^-t) cos2t
D
5 (e^-t) cos2t
Que.
31
Laplace transform of (e^-at) f(t) is
A
F(s) (e^-at)
B
F(s-a)
C
F(s+a)
D
F(s)/(s +a)
Que.
32
|Adj A| is equal to
A
|A|^n
B
|A|^(n-1)
C
|A|^(n+1)
D
|A^-1|
Que.
33
About the fourier series expansion ofa perodic function it can be said
that
A
Even function have only a constant and cosine terms in there
FS expansion
B
odd function have only sine terms in there FS expansion
C
functions with half wave symmetry contain only odd harmonics
D
all above the three
Que.
34
the final value of [(L^-1)(2s+1)]/[(s^4)+8(s^3)+16(s^2)+s] is
A
infinity
B
2
C
1
D
0
Que.
35
The fourier transform of a Gaussian time pulse is
A
uniform
B
A pair of impulses
C
Gaussian
D
Rayleigh
Que.
36
The discrete time system described by y(n)=x(n)^2 is
A
causal,linear and time varying
B
causal,non-linear and time varying
C
non-causal,linear and time invarying
D
non-causal,non-linear and time variant
Que.
37
Which one of the following transfer functions does correspond to a non-minimum
phase system?
A
s/[(s^2)+2s+1]
B
(s+1)/[(s^2)+2s+1]
C
(s+1)/[(s^2)+2s-1
D
(s-1)/[(s^2)+2s+1]
Que.
38
The electromechanical closed loop control system has the following characteristic
equation: [(s^3)+6K(s^2)+(K+2)s+8]=0 where K is the forward gain
of the system.the condition for closed loop stability is
A
K=0.528
B
K=2
C
K=0
D
K=-2528
Que.
39
Which of the following signal is/are periodic?
A
S(t)=cos2t+cos3t+cos5t
B
S(t)=exp[j8(pi)t]
C
S(t)=exp(-7t)sin10(pi)t
D
S(t)=cos2tcos4t
Que.
40
A secound-order system has a transfer function given by G(s)=25/[(s^2)+8s+25]
If the system,initally at rest is subjected to a unit step input at t=0,the
secound peak in response will occur at
