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Description
Transcript
z dz
1. Evaluate the following integral
2 4i
z 2 dz
2
16i
88
3
16i
B.
32
3
C. 16i 88
D. 16i 96
A.
2. Find the value of X, if the determinant of the following matrix is ZERO.
A.
B.
C.
D.
X = 3 or X = 6
X=3
X = 3 or X = 3/2
X=6
3. Solve
, given
and
A.
B.
C.
D.
4. Evaluate
counter clockwise around the path , where
A. 2 i e1 1
1
B. 1
e
1
C. 2 i 1
e
D. 2 i 1 e2
3
is the circle
5. If x, y, z 3x 2 y y 3 z 2 , then at the point (1, -2, -1) has the following value
A.
B.
C.
D.
2
6. The complete solution of d y y cos 2 x is
dx 2
1
A. sin 2 x
3
1
B. e 2 x ( A cos x B sin x) cos 2 x
3
1
C. A cos x B sin x cos 2 x
3
1
D. sin 2 x
3
. The eigen values of A2 are
7. The matrix A is defined as
A.
B.
C.
D.
1, 3, -2
1, 9, 4
-1, -9, -4
-1, -3, 2
8. If
, then
will be
A.
B.
C.
D.
9. The Laplace transform of
3
4
3
B.
2
A.
is
6
s
s
6
5/2
s
s
5/2
4
3
4
3
D.
2
C.
10. Fourier
6
s
s
6
3/2
s
s
3/2
coefficient
a0
in
the
Fourier
series
f ( x) e x ; 0 x 2 is
A.
1 e
1
2
1
1 e2
2
1
C.
1 e2
B.
D.
e
2
2
1
11. If
is a singular matrix, then
A.
B.
C.
D.
12.
-2
0
2
-1
where
is a vector, is equal to
A.
B.
C.
D.
13. For the given matrix
,
is
A.
B.
5
is
a0
an cos nx bn sin nx
2 n1
of
C.
D.
14. Find the Laplace transform of
A.
B.
C.
D.
15. In the spherical coordinate system, two vectors
are situated at a point ( ,
) = (3, 45, 45). The value of
A.
B.
C.
D.
and
will be
14
75
41
121
16. For the given differential equation,
d 2 y dy
2y 0
dx 2 dx
The general solution is
A.
B.
C.
D.
y(x)= Ae-2x + Bex
y(x)= Ae2x - Be-x
y(x)= Ae2x + Bex
y(x)= Ae-2x + Be-x
17. If the two dice are independent, the probability for throwing two sixes with these dice is
A.
B.
C.
D.
6
18. The solution of
, given
is
A.
B.
C.
D.
19. The radius of convergence of the series
A.
B.
C.
D.
is
<2
20. Given the Laplace transform
then,
is
A.
B.
C.
D.
21. Given
yz
, then curl
is
A.
B.
C.
D.
22. If Laplace transform of f(t) is
then Laplace transform of t f(t) is
A.
B.
C.
D.
7
23. The value of
A.
B.
C.
D.
, where
for
3
0
9
1
24. The solution to the differential equation
A.
B.
C.
D.
is
are the family of
Straight lines with different intercepts on y-axis
Circle with different radii
Circle with different centers
Slight line with different slopes
25. Fourier transform of
is proportional to
A.
B.
C.
D.
26. The next iterative root for x 2 4 0 using Newton Raphson method if the initial guess is
3, is
A.
B.
C.
D.
4.2
3.833
1.8
2.167
27. Laplace transform of a unit impulse function is
1
s2
B. 1
C. -1
1
D.
s
A.
8
28. Six simple harmonic oscillations each of same frequency and equal amplitude are
superimposed. The phase difference between any two consecutive oscillations, i.e.,
n n1 is constant, where n is the phase of the nth oscillation. If the resultant
amplitude of the superimposition is zero, what is the phase difference
?
A. 2
B.
3
C.
6
D.
2
29. Which option best describes the Simpson’s 1/3 rule?
A.
B.
C.
D.
30. In use of Bisection method to solve the equation
–
, if the initial
interval is chosen as
after the first iteration, the root is seen to lie in the
interval
A.
B.
C.
D.
31. In the following circuit, the voltages at the nodes a, b and c respectively are
A.
B.
C.
D.
10 V, -4 V, 14 V
14 V, -12 V, 4 V
10 V, -12 V, 4 V
14 V, -12 V, 2 V
9
32. Maximum power that can be delivered to load RL by the network shown in the figure is
A.
B.
C.
D.
5W
8W
1W
3W
33. In the circuit shown below, if the source voltage Vs=100∠53.13o V then the Thevenin's
equivalent voltage in volts as seen by the load resistance RL is (Use tan-1 (4/3)=53.13o )
A.
B.
C.
D.
800∠53.13o
100∠90o
800∠90o
100∠53.13o
34. In the circuit shown below, the knee current of the ideal Zener diode is 10 mA. To
maintain 5 V across RL , the minimum value of RL in ohms and the minimum power rating
of the Zener diode in mW, respectively, are
A.
B.
C.
D.
125 and 250
125 and 125
250 and 125
250 and 250
35. What will be the (W/L) ratio of the MOSFET used in source follower with the power
budget of 10 mW, voltage gain of 0.5 and is driving a 50 ohm load?
(given that µn Cox =100 µA/V2 , Vth = 0.5 V, λ=0 and VDD =2 V)
A.
B.
C.
D.
100
300
200
400
10
36. A MOSFET carries a drain current of 1 mA with VDS = 0.5 V in saturation. The new drain
current and output impedance if VDS rises to 1 V respectively are given by
(assume λ=0.1 V-1 )
A.
B.
C.
D.
1.048 mA and 10.42 kΩ
2 mA and 10.42 kΩ
1.048 mA and 50 kΩ
2 mA and 50 kΩ
37. A degenerated CE stage is biased at a collector current of 1 mA. If the circuit provides a
voltage gain of 20 with no emitter degeneration and 10 with degeneration, then R C and RE
are given by
A.
B.
C.
D.
RC = 1 kΩ and RE = 1 kΩ
RC = 1 kΩ and RE = 26 Ω
RC = 520 Ω and RE = 5 kΩ
RC = 520 Ω and RE = 26 Ω
38. For the given circuit, choose the correct value of
that places the transistor at the edge
of saturation. It is also given that the same transistor in the same circuit with
operates in saturation and drains 200 µA of current. VT H is 0.4 V and λ=0.
A.
B.
C.
D.
39. Choose the correct value for base and collector biasing voltage.
(Assume β = 45 and VBE = 0.7 V)
A.
B.
C.
D.
VC = -4.48 V and VB = +8.3 V
VC = -4.48 V and VB = -8.3 V
VC = +4.48 V and VB = -8.3 V
VC = -8.3 V and VB = -4.48 V
11
40. If the impedance of a series connected resistor and inductor is expressed as
, where
is the angular velocity. What would be the admittance of a
parallel inductor-resistor
network?
A.
B.
C.
D.
41. In the following op-amp circuit, the voltage gain of the op-amp circuit will be,
A.
B.
C.
D.
19.5
17.66
1.32
26
42. Find the Thevenin equivalent (VTH and RTH ) between terminals A and B of the circuit
given below
A.
B.
C.
D.
4.67 V, 120 Ω
41.67 V, 120 Ω
41.67 V, 70 Ω
4.16 V, 70 Ω
12
43. For the circuit shown below, find Vy if iz is -3A
A.
B.
C.
D.
12 V
11 V
10 V
15 V
44. Consider the circuit shown below with
and
for t≥ 0. The energy
supplied by the element over the first second of operation is ( assume v and i are zero for
t< 0)
i
-
+
v
A.
B.
C.
D.
45. The value of R in the circuit shown below is
A.
B.
C.
D.
25 Ω
15 Ω
20 Ω
10 Ω
13
46. A dc supply of 35 V is connected across 600 Ω resistance in series with an unknown
resistance. The voltmeter having a resistance of 1.2 kΩ is connected across 600 Ω
resistance which reads 5 V. Then the unknown resistance should be
A.
B.
C.
D.
50 Ω
2.4 kΩ
1.7 k Ω
7.2 Ω
47. For the circuit shown below, the value of current ‘i’ is
A.
B.
C.
D.
0.455 A
0.224 A
0.234 A
0.425 A
48. In the circuit shown below, the power extracted by the 2 A current source from its circuit
is
A.
B.
C.
D.
40 W
20 W
50 W
30 W
14
49. The rms value of the wave in figure shown below is approximately
A.
B.
C.
D.
25 V
90 V
80 V
50 V
50. In the circuit shown below the switch is closed at t=0. At t=0+ , the current through the
capacitor is
A.
B.
C.
D.
4.2 A
2A
4A
2.4 A
51. For a series resonant circuit,
circuit is
A.
B.
H and
Hz
Hz
C.
Hz
D.
Hz
15
F. The bandwidth of the
52. Power is drawn from a source at power factor of
A.
B.
C.
D.
. If Pav = 300 W, the reactive power is
106 VA
0 VA
100 VA
103 VA
53. Given that the transfer function of a network, H(s) =
input, then
A.
B.
C.
D.
and
is a unit step
in steady state is
4/9
4/3
0
∞
54. The diodes and capacitors in the circuit shown below are ideal. The voltage V(t) across
diode D1 is
V(t)
1
D2
1
C1
2
A.
B.
C.
D. 1
D1
C2
2
cos(wt)
0
55. A graph of an electrical network has 4 nodes and 7 b ranches. The number of links
with respect to the chosen tree, would be
A.
B.
C.
D.
2
4
3
5
56. Pinch-off voltage VP for an FET is the drain voltage at which
A.
B.
C.
D.
Zener break down takes place
Significant drain current starts flowing
Avalanche break down takes place
All free charges get removed from the channel
16
57. Barrier potential in a p-n junction is caused by
A.
B.
C.
D.
Thermally generated electrons and holes.
Diffusion of majority carriers across the junction
Migration of minority carriers across the junction.
Flow of drift current.
58. Which is the suitable biasing for cutoff mode of bipolar transistor
A.
B.
C.
D.
VEB is at forward bias while VCB is at reverse bias
VEB is at forward bias while VCB is also at forward bias
VEB is at reverse bias while VCB is also at reverse bias
VEB is at reverse bias while VCB is at forward bias
59. If the energy distribution per unit volume per unit energy of the electron is nE(E) in the
conduction band is given by
(were A is constant),
then the maximum energy distribution occurs when E-Ec equals to
A.
B.
C.
D.
60. Hall effect measurement provides
A.
B.
C.
D.
Carrier sign only
Carrier concentration & Carrier sign
Carrier concentration only
Carrier effective mass
61. A certain Si (relative dielectric constant = 11.2) JFET has channel length 0.1 µm, and the
electron concentration of 7 × 1017 /cm3 and the pinch-off voltage is
(given = 8.858 ×10-12 F/m)
A.
B.
C.
D.
50 V
11.2 V
5.64 V
6.66 V
17
62. If 1.0 mm2 cross sectional area of Silicon bar with ND-NA = 1016 /
of 50 mA, then the drift velocity of the carrier is
A.
B.
C.
D.
carrying a current
4.3 × 102 cm/s
1.2 × 103 cm/s
3.7 × 102 cm/s
3.1 × 103 cm/s
63. Fermi level in p-type semiconductor is
A.
B.
C.
D.
64. The forward bias current in Schottky barrier diode is due to
A.
B.
C.
D.
Avalanche breakdown
Thermionic emission
Zener tunneling
Recombination
65. An n-type semiconductor is
A.
B.
C.
D.
Obtained by doping intrinsic semiconductor with trivalent impurity
Obtained by doping intrinsic semiconductor with pentavalent impurity
Not neutral
Always in ionic form
66. For a forward biased semiconductor diode given that
= 37.5 mV at some temperature
and the bias current of 12.5 mA . The dynamic slope resistance will be
A.
B.
C.
D.
13
25
4
3
18
67. For a semiconductor sample, given that its intrinsic resistivity at 300 K is 0.47 -m, the
charge on an electron is
C, the electron and hole motilities are 0.39 and
2
0.19 m /V-s respectively at 300 K. The intrinsic carrier concentration will be
/m3
/m3
/m3
/m3
A.
B.
C.
D.
68. Given that the resistivity of a p-type semiconductor is
-m. The hole mobility is
2
0.03 m /V-s. Assuming that the conductivity due to electrons is negligible, the Hall
coefficient will be
m3 C
m3 C
mC
m3 C
A.
B.
C.
D.
69. A Zener diode has a DC power dissipation rating of 600 mW and the Zener diode has a
voltage rating of 10 V. The maximum current that can flow through Zener diode will be
A.
B.
C.
D.
60 µA
6000 µA
60 mA
16.66 mA
70. Which of the following is used for detecting light intensity?
A.
B.
C.
D.
LED
Tunnel diode
Zener diode
Photodiode
71. For a transistor IB = 100 µA and IC = 2 mA. The values of and of the transistor
respectively, are
A.
B.
C.
D.
200 and 9.5
0.95 and 20
20 and 0.95
9.5 and 200
19
72. ‘Early effect’ in BJT refers to
A.
B.
C.
D.
Avalanche breakdown
Zener breakdown
Thermal breakdown
Base narrowing
73. For depletion mode n-type MOSFET, the gate voltage must be
A.
B.
C.
D.
High positive
Low positive
High negative
Zero
74. The intrinsic stand - off ratio of a UJT is 0.60.The interbase resistance is 7 k. The static
values of base resistance (say RB1 and RB2 ) respectively are
A.
B.
C.
D.
4.2
6.0
3.0
5.0
k
k
k
k
and
and
and
and
2.8 k
1.0 k
4.0 k
2.0 k
75. The resolution in photolithography is limited by
A.
B.
C.
D.
Diffraction
Interference
Refraction
Polarization
76. An AM broadcast station operates at its maximum allowed total output of 50 kW and at
50% modulation. How much of its transmitted power is intelligence (sidebands)?
A.
B.
C.
D.
5.5 kW
2.15 kW
7.5 kW
15.5 W
77. A 7 kHz modulating frequency modulates a 107.6 MHz wave so as to produce a
frequency deviation of 50 kHz. The carrier swing of the resulting frequency modulated
signal is
A.
B.
C.
D.
100 kHz
25 Hz
75 kHz
50 kHz
20
78. An 8 kbps NRZ coded data stream is used in a digital communication link. The minimum
bandwidth required for the communication link is
A.
B.
C.
D.
6 kHz
4.5 kHz
4 kHz
5.5 kHz
79. The transmit power of a cellular phone is 0.8 W. The phone is transferring digital data at a
rate of 9600 bps. The energy per bit, Eb , for the data transmission is
A.
B.
C.
D.
83.36
73.36
83.56
73.56
µJ
µJ
µJ
µJ
80. The bandwidth of a channel is 4 kHz. The maximum capacity of a telephone channel that
has S/N ratio of 1023 (60dB), is
A.
B.
C.
D.
60,000 bits/s
40,000 bits/s
50,000 bits/s
20,000 bits/s
81. A system has three stage cascaded amplifier with power gains
figures
Then the overall noise figure is
and the noise
A.
B.
C.
D.
82. Calculate the maximum range of a radar system which operates at 5 cm with peak pulse
power of 125 kW, if its minimum receivable power is
W, the capture area of its
antenna is 5
, and the radar cross sectional area of the target is
.
A.
B.
C.
D.
200 km
400 km
300 km
500 km
21
83. For an AM signal, the bandwidth is 10 kHz and the highest frequency component present
is 705 kHz. The carrier frequency used for this AM signal is
A.
B.
C.
D.
700 kHz
695 kHz
705 kHz
710 kHz
84. A TDM link has 20 signal channels and each channel is sampled 8000 times/sec. Each
sample is represented by seven binary bits and contains an additional bit for
synchronization. The total bit rate of TDM link is
A.
B.
C.
D.
1280 Mbps
1180 kbps
1180 Mbps
1280 kbps
85. An antenna can be modeled as an electric dipole of length 4 m at 3 MHz. If the current is
uniform over its length, then the radiation resistance of the antenna is
A.
B.
C.
D.
86. A 70 km microwave link is functioning at 3 GHz with the antennas of same gain equal to
60 dB. If the power radiated by the transmitting antenna is 22 W, the received power
considering the free space path loss is
A.
B.
C.
D.
22
87. A system has a receiver noise of 50 Ω. It is connected to an antenna with an input
resistance of 50 Ω. The noise figure of the system is
A.
B.
C.
D.
50
1
2
101
88. A DSB modulated signal
is mixed (multiplied) with a local
carrier
and the output is passed through a low pass filter (LPF)
with bandwidth equal to the bandwidth of the message signal
. What will be the
output of the LPF?
A
mt cos2f c
2
A
mt cos2f c
B.
2
A
mt cos
C.
2
A
mt cos4f c
D.
2
A.
89. If the sampling rate is 10000 samples/sec and the step size is Δ=0.1 and a 1 kHz
sinusoidal signal input is given to a delta modulator, the maximum amplitude of this
signal which will prevent slope overload, is
1
0.1
1
B.
1
C.
10
1
D.
2
A.
90. Suppose a vehicle is coming at a speed of 360 km/hr to a base station in a mobile cellular
communication system, The signal is narrowband and transmitted at a center frequency of
1 GHz. The Doppler shift is
A.
B.
C.
D.
±360 Hz
±771.6 Hz
±333.34 Hz
±100.12 Hz
23
91. In a super heterodyne receiver, the IF is 455 kHz. If it is tuned to 1200 kHz, the image
frequency is
A.
B.
C.
D.
2110 kHz
745 kHz
910 kHz
1655 kHz
92. The noise figure of a receiver is 1.6. Its equivalent noise temperature is (given
C)
A.
B.
C.
D.
174 K
180 K
464 K
-180 K
93. In the phase modulation, the frequency deviation is
A.
B.
C.
D.
Directly proportional to modulating signal frequency.
Inversely proportional to modulating signal frequency.
Inversely proportional to the square root of the modulating frequency.
Independent of the modulating signal frequency.
94. A carrier is simultaneously modulated by 2 sine waves with modulation indices of 0.3 and
0.4, the total modulating index is
A.
B.
C.
D.
1
0.7
0.5
1.2
95. Rather than sending the absolute value of each sample it is possible to achieve a smaller
transmission bit rate by sending the difference between consecutive samples, This is
known as
A.
B.
C.
D.
Delta Modulation
Delta-Sigma Modulation
Pulse code Modulation
Pulse amplitude Modulation
24
96. How many AM broadcast station can be accommodated in a 100 kHz bandwidth if the
highest frequency modulating a carrier is 5 kHz
A.
B.
C.
D.
20
10
25
5
97. Noise interference in flat top PAM is
A.
B.
C.
D.
Greater than ideal and natural sampling
Greater than natural sampling
Smaller than natural sampling and greater than ideal sampling
Smaller than ideal and natural sampling
98. Which of the following operation results in
?
1.
2.
3.
Select the correct answer using the options given below
A. Only 1 and 2
B. Only 1 and 3
C. Only 2 and 3
D. 1, 2 and 3
99. The dominant mode of propagation of medium wave (MW) broad cast signal is by
A.
B.
C.
D.
Sky wave
Ground wave
Line-of-sight
Tropospheric
100. The output signal from an AM modulator is
The message signal
A.
B.
C.
D.
and the carrier
and
and
and
and
25
are given by,
101. A wire is drawn as shown in the figure and carries a current Io . The magnetic field at the
centre O of the semicircular path of radius R is
A.
0 I 0
into the paper
2R
0 I 0
B.
out of the paper
4R
I
C. 0 0 into the paper
4R
I
D. 0 0 out of the paper
2R
I0
o
102. When alternating current passes through a conductor
A.
B.
C.
D.
It remains uniformly distributed throughout the section of conductor
Portion of conductor near the surface carries less current as compared to the core
Entire current passes through the core of the conductor
Portion of conductor near the surface carries more current as compared to the core
103. For a transmission line of characteristic impedance Z0 terminated in a load impedance ZL,
Z
the reflection coefficient at the load is . The ratio L is
Z0
1
1
1
B.
1-
C.
1-
D.
1
A.
104. A distortionless transmission line is one in which
A. The phase constant and attenuation constant are both frequency independent.
B. The phase constant and the attenuation constant both depend linearly on
frequency.
C. The attenuation constant is zero.
D. The phase constant depends linearly on frequency while the attenuation
constant is frequency independent.
26
105. A family of arcs is obtained in the Smith Chart by varying the normalized reactance in the
range
A.
B.
C.
D.
0 to
1 to
to
0 to1
106. If the electrostatic potential is given by V V0 x 2 y 2 z 2 where V0 is a constant, then
the charge density which gives rise to the above potential would be
A. 6V0 0
B. Zero
C. 2V0 0
D.
V0
0
107. The radiation resistance of a
A.
B.
C.
D.
dipole is
2
73
75
120
377
108. In a certain medium E 10 cos(108 t 3 y) x . What type of medium is it?
A.
B.
C.
D.
Lossy dielectric
Lossless dielectric
Free space
Good Conductor
109. Polarization in a dielectric material is given by
A. P ( r 1) E
B. P 0 ( r 1) E
C. P r E
D. P 0 ( r 1) 0
27
110. The electric field of a uniform electromagnetic plane wave in free space propagating
along the positive x-direction is given by E 10( yˆ jzˆ)e j 22x . The frequency and
polarization of the wave is
A.
B.
C.
D.
1.2 GHz and right circular
1.2 GHz and left circular
4 GHz and left circular
4 GHz and right circular
111. If the power of an electromagnetic wave attenuates as P P0 e -z , then the attenuation in
dB is
4.343
B. 4.343
C.
8.686
D. 8.686
A.
112. An infinitely long uniform solid wire of radius a carries a uniform dc current of current
density J . The magnetic field at a distance r from the centre of the wire is proportional to
A. r for r a and 1
r2
for r a
B. r for r a and 1 for r a
r
C. 0 for r a and 1 for r a
r
D. 0 for r a and 1 2 for r a
r
113. A transmission line with characteristic impedance of 100 is used to match a 50
section to a 200 section. If the matching is to be done both at 200 MHz and 1 GHz, the
length of the transmission line is
A.
B.
C.
D.
37.5 cm
7.5 cm
15 cm
3.75 cm
28
114. A plane wave propagating in air with E 5e j (t 3 x4 y ) ẑ V/m is incident on a perfectly
conducting slab positioned at x 0 . The E field of the reflected wave is
A. E 5e j (t 3 x4 y ) ẑ V/m
B. E 5e j (t 3 x4 y ) ẑ V/m
C. E 5e j (t 3 x4 y ) ẑ V/m
D. E 5e j (t 3 x4 y ) ẑ V/m
115. A lossless coaxial cable filled with a dielectric of relative permittivity 2.25 has a
characteristic impedance of 75 . The per unit length parameters L and C are
A.
B.
C.
D.
375 nH and 0.066 nF
375 nH and 0.66 nF
37.5 nH and 0.11 nF
375 nH and 0.11 nF
116. For a wave in a medium the angular frequency and wave vector k are related by
2 (02 c 2 k 2 ) , where 0 and c are constants. The product of group and phase
velocity, i.e., v g v p is
A. 0.25c 2
B. 0.4c 2
C. 0.5c 2
D. c 2
117. Equipotential surfaces corresponding to a particular charge distribution are given by
4 x 2 ( y 2) 2 z 2 Vi , where Vi is a constant. The electric field at the origin is
A. E 4 yˆ
B. E 0
C. E 2 xˆ
D. E 4 yˆ
29
118. The magnetic field vector of a plane wave is given by
H 10 sin(50000t 0.004 x 30) yˆ
The phase velocity is,
A.
B.
C.
D.
1.25×107 m/s
3×108 m/s
-3×108 m/s
-1.25×107 m/s
119. The electric and magnetic fields for a plane wave in a homogeneous non-conducting
4
medium for which
r 1, are given by E 30 exp j t y aˆ z and
3
4
H 1.0 exp j t y aˆ x . The value of the relative permittivity is
3
A.
B.
C.
D.
16
8
4
32
120. A conducting sphere of radius R has charge +Q on its surface. If the charge on the sphere
is doubled and its radius is halved, the electric field near the surface will
A.
B.
C.
D.
Increase 4 times
Decrease 8 times
Increase 8 times
Decrease 4 times
121. The vector potential in a region is given as A yiˆ 2 xjˆ . The associated magnetic
induction B is
A. iˆ kˆ
B. iˆ 2 ˆj
C. 3kˆ
D. iˆ ˆj kˆ
122. A rectangular metal waveguide filled with a dielectric material of relative permittivity
r 4 has the inside dimensions 3.0 cm x 1.2 cm. the cut-off frequency for the dominant
mode is
A. 2.5 GHz
B. 5.0 GHz
30
C. 10 GHz
D. 12.5 GHz
123. In free space, if electric field is given as E 20 cost 50 x aˆ y , then the displacement
current density Jd is
A. 20 0 sint 50 x aˆ y
B. 20 0 sint 50 x aˆ y
C. 20 sint 50 x aˆ y
D. 20 sint 50 x aˆ y
124. Given an inhomogeneous current density J 3 y 2 zaˆ x 2 x3 zaˆ y zaˆ z , find the total current
passing through a square surface at x = 1 in the aˆ x direction. The dimensions of the
surface are 1 y 2 , 1 z 2 .
A.
B.
C.
D.
8.5 A
10.5 A
7A
14 A
125. A uniform plane wave in air impinges at 45 o angle on a lossless dielectric material with
dielectric constant εr. The transmitted wave propagates in a 30 o direction with respect to
the normal. The value of εr is
A. 1.5
B. 2
C. 2
D.
1.5
126. A material has conductivity of 10-2 mho/m and a relative permittivity of 4. The frequency
at which the conduction current in the medium is equal to the displacement current is
A.
B.
C.
D.
450 MHz
90 MHz
45 MHz
900 MHz
31
127. If a signal of 30 MHz is transmitted through a coaxial cable, which has a capacitance of
40 pF/m and an inductance of 900 nH/m. The phase velocity and characteristic impedance
for a 2 meter long cable is given by,
A.
B.
C.
D.
128. A
1.66108 m/s, 150
1.66109 m/s, 150
3.32108 m/s, 300
1.66109 m/s, 300
light
beam traveling
in
x-direction
is described
by
the
electric
field
An electron is constrained to move along the y-direction
with speed of 2.0 × 107 m/s. The maximum magnetic force on the electron is
A.
B.
C.
D.
0N
20 N
1.6 × 10-18 N
3.2 × 10-18 N
129. The SI unit for Poynting vector
A.
B.
C.
D.
is
W.m2
J.m2
J/m2
W/m2
130. A 75 Ω quarter wave transformer is connected to a 125 Ω TV receiver. The input
impedance of this transformer is
A.
B.
C.
D.
25
75
100
45
131. If a coaxial cable has an inner conductor diameter of a cm and the inner diameter of the
outer conductor b cm, the conductivity of the conductors is and the permittivity of the
filled medium is . Conductance per unit length of this coaxial transmission line is
A.
2
b
ln
a
32
2
b
ln
a
1
C.
b
2 ln
a
1
D.
b
2 ln
a
B.
132. A lossless transmission line used in a TV Receiver has a capacitance of 50 pF/m and an
inductance of 20 nH/m. The characteristic impedance of a 10 meter long line is
A.
B.
C.
D.
10
40
20
30
133. A lossless transmission line in air with characteristic impedance of 75 and length 1 cm
is short circuited. At 9 GHz, the input impedance at the other end of the transmission line
is
A. Capacitive
B. Inductive
C. Zero
D. Resistive
134. A lossless transmission line of length 50 cm with L = 10 μH/m, C = 40 pF/m is operating
at 25 MHz. Its electrical path length is
A.
B.
C.
D.
π radians
π/2 radians
0.5 metres
0.75 metres
135. A lossless transmission line is terminated in a load which reflects a part of the incident
power. The measured VSWR is 2, the percentage of the power that is reflected back is
A.
B.
C.
D.
11.11
57.73
33.33
0.11
33
136. In a square coaxial transmission line shown in the figure, if the space between the
conductors is filled with a material having a relative permittivity of 4.0 and the
capacitance per unit length is 6.0 F/m, the characteristic impedance of this line is
A.
B.
C.
D.
10π
20π
40π
30π
2 mm
2 mm
4 mm
137. A source of 10 mW is connected to an attenuator of 20 dB. At the output of the
attenuator, the power is
A.
B.
C.
D.
100 mW
2 mW
0.1 mW
0.5 mW
138. Electromagnetic waves which are commonly referred to as microwave correspond to
wavelength range,
A.
B.
C.
D.
mm
µm
cm
nm
cm
mm
cm
µm
139. Which of the following is not used to generate microwaves,
A.
B.
C.
D.
Magnetron
Cyclotron
Klystron
Gunn diode
140. An attenuator is formed by operating an air-filled waveguide below cutoff as shown in the
figure given below. If a is 7.5 cm, the frequency range
of operation in GHz for this
attenuator will be,
a
A.
B.
C.
D.
34
0.6a
141. On a lossless 50 transmission line, the reflection coefficient is
located
at a point
from the termination. The termination impedance is
4
A.
B.
C.
D.
142. If the memory chip size is 256 × 1 bits, then the number of chips required to make up
1K(1024) bytes of memory is
A.
B.
C.
D.
32
16
24
8
143. A computer program that converts an entire program into machine language at one time is
called
A.
B.
C.
D.
CPU
Interpreter
Compiler
Simulator
144. Given the binary 00000111, its 2’s compliment is obtained and expressed in hexadecimal
form, the result is
A.
B.
C.
D.
F9
F8
-79
-89
145. In C language, which of the following statements should be used to obtain a remainder
after dividing 3.14 by 2.1?
A.
B.
C.
D.
rem = 3.14 % 2.1
rem = fmod (3.14, 2.1)
rem = modf (3.14, 2.1)
Remainder cannot be obtain in floating point division.
35
146. In C++, what is the output of the following code
char symbol[3]={‘a’,‘b’,‘c’};
for (int index=0; index<3; index++)
cout << symbol [index];
A.
B.
C.
D.
abc
abc
“abc”
‘abc’
147. In C++, the values of x, m and n after the execution of the following statements are
int x, m, n;
m = 10;
n = 15;
x = ++m + n++;
A.
B.
C.
D.
x=25,
x=27,
x=26,
x=27,
m=10,
m=11,
m=11,
m=10,
n=15
n=16
n=16
n=15
148. Which of the following is not an operating system?
A.
B.
C.
D.
iOS
Xeon
Ubuntu
RedHat
149. Which of the following is not a sub system of GSM architecture?
A.
B.
C.
D.
NSS
BSS
MSC
OSS
150. Simplify the Boolean function
A.
B.
C.
D.
36
FOR ROUGH WORK
37
FOR ROUGH WORK
38