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Q.l Q 25 carry one mark each
Q.1
f
A=
0
in
logic
expre
ssion
Z =[A
EF
BC D] [A+
DE
BC DEL then
(A) Z = 0 (B) Z =
(C)
Z= BC (D)
Z=
BC
Q 2
A
card
is
drawn at random
from
an
ordinary
deck
of 52 playing cards.
f
we
are told
that
card is heart
1
then information is
(A)
2.12 bi ts (B) 2
bits
(C)
3.46
bi t
s (
D)
31.36
bi t
s
Q 3
A
DS/BPSK
spread
spectrum signal
has
a processing
gain of
500. f the desired
error
probability
is 10
5
and
cb/
J
0
) required to obtain an error probabilit
y
of
10
5
for
binary
PSK
is 9.5
dB
1
then the
Jamming
margin against
a
containers tone
jammer is
(
A
23.6 dB (B) 17.5 dB
(C)
117.4 dB
D)
109.0 dB
Q 4
A
60
n
coaxial cable feeds a
75
+
j25
n
dipole
antenna.
The
voltage reflection
coefficient
r and standing
wave
ratio s are
respectively
A
) 0.212 L48.55 o 1.538 (B) 0.486 68.4o 2.628
(C) 0.486 L41.45 o 2.682
D
) 0.212L68.4
1
1.538
Q 5
The
directive gain
of an
antenna is 36 dB. t the antenna radiates 15 kW
at
a
distance
of
60
km
1
the
time
average power
density
at that
distance
is
A
) 9.42 f W / m
2
(B) 6.83 m W/ m
2
C
) 1.32
mW
m
2
D
) 10.46
mW
m
2
Q 6 f
A is a
3-
rowed
square matrix such that I
A
I
2
1
then I
dj (
adj
A
2
) I
is
equal to
(A) 2
4
(B) 2
8
(D)
None
of
these
Q.7
[
2
log
tan x x
is
equal to
C
) ;
log,2
(D)
None
of
these
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Q.8 An
anti-aircraft
gun
can take a
maximum of
4
shots
at
an enemy
plane moving away
from it. The probabilities
of hitting
the plane at
the
first, second, third
and fourth shot
are
0.4, 0.3, 0.2
and
0.1 respectively.
The
probability
that
the
gun hits
the plane is
A) 0.76 B) 0.4096
C) 0.6976
D)
None
of these
Q.9 The
following fields exist in charge free regions
Q.10
P =
60sin wt +lOx)
z Q = lO cos wt-
2p)
p
The
possible
electromagnetic
fields are
A) P Q
C) P R
S = ls inBsin wt-
6r ue
r
B) R S
D)
Q S
A random process
has the
power
density
spectrum
Pxx w =
6
u u
3
. The
average
power
in
process is
[
+ )
A) 1/4
C) 5/8
B) 3/8
D)
1/2
Q.11 The Bode
plot shown below
represent
d
100 dB
~ ~ w
A 100s
2
)
1
+ O.ls)
3
100s
2
C)
1
+ O.ls)
5
w 10
B)
1000s
2
1
+ O.ls)
3
D)
lOOOi
1 + O.ls)
5
Q.12 he
forward
transfer
function
of
a
ufb system
is
s =
8
~
2
) .
The system
1s stable
for
A) K < 1
C)
K
2
B) K > 1
D)
K
2
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Q 13 Consider
the ufb system shown
below
R s ) - , ~ 1
lt------ -J
s)
The root-loci,
as o.
is varied, will be
j.JJ
A)
-1
B)
C)
1
D)
Q 14
The Fourier series coefficient for the periodic signal shown
belo
w is
x t)
I I
I I I I
TI
4TI
~ ~ ~ ~ ~ ~ ~ ~ t
0
TI
4TI
3 3
A)
2 ~ k e
: \ 4 k - 1
(
.4d) )
(C) e
1
- 3
1
2nk
Q 15 Th
e
z transform
of
3n
u
1]
is
A)
3: z l I>
3
C) 3 ~
z l z I>
3
B) j 2 ~ k e
:\
k
)-1
D)
2 n 1 e - 1
B) 3 :
z I I
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