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This section includes 682 Mcqs, each offering curated multiple-choice questions to sharpen your Electrical Engineering knowledge and support exam preparation. Choose a topic below to get started.
51. |
The time constant and R-C circuit may also be defined as the time during which thecharging current falls to percent of its initial maximum value, |
A. | 37 |
B. | 42 |
C. | 63 |
D. | 73 |
Answer» B. 42 | |
52. |
The input impedance of a quarter wave line 50 ohm and load impedance of20 ohm is |
A. | 50 |
B. | 20 |
C. | 1000 |
D. | 125 |
Answer» E. | |
53. |
The transmission coefficient is given by 0.65. Find the return loss of thewave. |
A. | 9.11 |
B. | 1.99 |
C. | 1.19 |
D. | 9.91 |
Answer» B. 1.99 | |
54. |
The total charge of a surface with densities 1,2,…,10 is |
A. | 11 |
B. | 33 |
C. | 55 |
D. | 77 |
Answer» D. 77 | |
55. |
at R = 4m and σ = -3 at R = 5m. Find the flux density at R = 6m. |
A. | 17/6 |
B. | -17/6 |
C. | 13/6 |
D. | -13/6 |
Answer» E. | |
56. |
Find the load impedance in a quarter line transformer with characteristicimpedance of 75 ohm and input impedance of 200 ohm. |
A. | 28.125 |
B. | 12.285 |
C. | 52.185 |
D. | 85.128 |
Answer» B. 12.285 | |
57. |
πεh).aN. State True/False. |
A. | true |
B. | false |
Answer» B. false | |
58. |
The current reflection coefficient of a line with voltage reflection coefficient of0.65 is given by |
A. | 0 |
B. | 0.65 |
C. | -0.65 |
D. | 0.35 |
Answer» D. 0.35 | |
59. |
The time constant of an R-C circuit is defined as the time during which capacitorcharging voltage actually rises to percent of its value. |
A. | 37, initial |
B. | 63.2, initial |
C. | 63.2, final |
D. | 37, final |
Answer» D. 37, final | |
60. |
For an infinite transmission line, the characteristic impedance is given by 50ohm. Find the input impedance. |
A. | 25 |
B. | 100 |
C. | 2500 |
D. | 50 |
Answer» E. | |
61. |
Find the characteristic impedance of a quarter wave with input and loadimpedances given by 50 and 25 respectively. |
A. | 50 |
B. | 25 |
C. | 75 |
D. | 35.35 |
Answer» E. | |
62. |
Electric displacement is a quantity. |
A. | scalar |
B. | vector |
C. | both of the above |
D. | none of the above |
Answer» C. both of the above | |
63. |
Those magnetic materials are best suited for making armature and transformer coreswhich have permeability and hystersis loss. |
A. | high, high |
B. | low, high |
C. | high, low |
D. | low, low |
Answer» D. low, low | |
64. |
According to Faraday’s law, EMF stands for |
A. | electromagnetic field |
B. | electromagnetic force |
C. | electromagnetic friction |
D. | electromotive force |
Answer» E. | |
65. |
The electromagnet has 50 turns and a current of 1A flows through the coil. If the lengthof the magnet circuit is 200 mm, what is the magnetic field strength ? |
A. | 2500 at/m |
B. | 250 at/m |
C. | 25 at/m |
D. | 2.5 at/m |
Answer» C. 25 at/m | |
66. |
Find the divergence of the vector F= xe-x i + y j – xz k |
A. | (1 – x)(1 + e-x) |
B. | (x – 1)(1 + e-x) |
C. | (1 – x)(1 – e) |
D. | (x – 1)(1 – e) |
Answer» B. (x – 1)(1 + e-x) | |
67. |
Find the receiving impedance of a transmission line having a voltage of 24Vand a conduction current of 1.2A is |
A. | 25.2 |
B. | 22.8 |
C. | 28.8 |
D. | 20 |
Answer» E. | |
68. |
The input impedance of a half wave transmission line with a load impedanceof 12.5 ohm is |
A. | 25 |
B. | 50 |
C. | 6.25 |
D. | 12.5 |
Answer» E. | |
69. |
The power of a wave of with voltage of 140V and a characteristic impedance of 50 ohmis |
A. | 1.96 |
B. | 19.6 |
C. | 196 |
D. | 19600 |
Answer» D. 19600 | |
70. |
Given the vector potential is 16 – 12sin y j. Find the field intensity at the origin. |
A. | 28 |
B. | 16 |
C. | 12 |
D. | 4 |
Answer» D. 4 | |
71. |
What is the potential difference between 10sinθcosφ/r2 at A(1,30,20) and B(4,90,60)? |
A. | 2.386 |
B. | 3.386 |
C. | 4.386 |
D. | 5.386 |
Answer» D. 5.386 | |
72. |
When the ratio of load voltage to input voltage is 5, the ratio of thecharacteristic impedance to the input impedance is |
A. | 1/5 |
B. | 5 |
C. | 10 |
D. | 25 |
Answer» C. 10 | |
73. |
at R = 4m and σ =-3 at R = 5m. Find the flux density at R = 4.5m. |
A. | 4/4.5 |
B. | 3/4.5 |
C. | 2/4.5 |
D. | 1/4.5 |
Answer» D. 1/4.5 | |
74. |
The transmission coefficient in a wave travelling through two media havingintrinsic impedances of 5.5 and 1.33 is |
A. | 0.389 |
B. | 0.55 |
C. | 0.133 |
D. | 0.42 |
Answer» B. 0.55 | |
75. |
The reflection coefficient of a transmission line having characteristic and loadimpedances as 50 and 30 ohm respectively is |
A. | 1/4 |
B. | 1/8 |
C. | 1/2 |
D. | 3/4 |
Answer» B. 1/8 | |
76. |
The incident wave amplitude is 24 units. Find the reflected wave amplitude ifthe reflection coefficient is 0.6. |
A. | 14.4 |
B. | 16.6 |
C. | 13.3 |
D. | 11.1 |
Answer» B. 16.6 | |
77. |
Find the potential of the function V = 60cos θ/r at the point P(3, 60, 25). |
A. | 20 |
B. | 10 |
C. | 30 |
D. | 60 |
Answer» C. 30 | |
78. |
When a transmission line has a load impedance same as that of thecharacteristic impedance, the line is said to be |
A. | parallel |
B. | perpendicular |
C. | polarized |
D. | matched |
Answer» E. | |
79. |
The power of the electromagnetic wave with electric and magnetic fieldintensities given by 12 and 15 respectively is |
A. | 180 |
B. | 90 |
C. | 45 |
D. | 120 |
Answer» C. 45 | |
80. |
Given that R = 20 ohm, L = 40 mH, C = 40 μF, G = 0.02 mho. Find whetherthe line is distortionless or not. |
A. | distorted line |
B. | distortionless line |
C. | all of the mentioned |
D. | none of the mentioned |
Answer» C. all of the mentioned | |
81. |
The centre of the point having a normalised resistance of 1.2 ohm andreactance of 1.5 ohm is |
A. | (0.54,0) |
B. | (0.45,0) |
C. | (0.36,0) |
D. | (0.78,0) |
Answer» B. (0.45,0) | |
82. |
The transmission coefficient in a wave travelling through two media havingpermittivities 4 and 1 is |
A. | 1/4 |
B. | 3/2 |
C. | 3/4 |
D. | 2/3 |
Answer» E. | |
83. |
A square cross-sectional magnet has a pole strength of 1 x 10 Wb and cross sectionalarea of 20 mm x 20 mm. What is the strength at a distance of 100 mm from the unit pole in air ? |
A. | 63.38 n/wb |
B. | 633.8 n/wb |
C. | 6338 n/wb |
D. | 63380 n/wb |
Answer» D. 63380 n/wb | |
84. |
kV. Find „a‟. |
A. | 1m |
B. | 1cm |
C. | 10cm |
D. | 1mm |
Answer» E. | |
85. |
When the length of the transmission line is same as that of the wavelength,then which condition holds good? |
A. | zin = zo |
B. | z = zo |
C. | zl = zo |
D. | zin = zl |
Answer» E. | |
86. |
The characteristic impedance of a transmission line with impedance andadmittance of 16 and 9 respectively is |
A. | 25 |
B. | 1.33 |
C. | 7 |
D. | 0.75 |
Answer» C. 7 | |
87. |
The reflection coefficient of a wave travelling through two media havingpermittivities 4 and 9 respectively is |
A. | 0 |
B. | 0.5 |
C. | 0.25 |
D. | 0.2 |
Answer» E. | |
88. |
A 200 turn coil having an axial length of 30 mm and a radius of 10 mm is pivoted in a magnetic field having a flux density of 0.8 T. If the coil carries a current of 0.5 A, the torque acting on the coil will be |
A. | 0.48 N-m |
B. | 4.8 N-m |
C. | 0.0048 N-m |
D. | 0.048 N-m |
Answer» E. | |
89. |
The simplest kind of capacitor is ________ |
A. | ceramic capacitor |
B. | electrolyte capacitor |
C. | tuning capacitor |
D. | paper capacitor |
Answer» E. | |
90. |
Paper capacitor is a type of _________ |
A. | fixed capacitor |
B. | variable capacitor |
C. | either fixed or variable depending on its usage |
D. | neither fixed nor variable |
Answer» B. variable capacitor | |
91. |
Displacement current depends on ___________ |
A. | moving charges |
B. | change in time |
C. | both moving charges and change in time |
D. | neither moving charges nor change in time |
Answer» C. both moving charges and change in time | |
92. |
In a variable capacitor, capacitance can be varied by ______ |
A. | turning the rotatable plates in or out |
B. | sliding the rotatable plates |
C. | changing the plates |
D. | changing the material of plates |
Answer» B. sliding the rotatable plates | |
93. |
Leakage in capacitors is primarily caused by _________ |
A. | transistors |
B. | resistors |
C. | inductors |
D. | dc motors |
Answer» B. resistors | |
94. |
The flow of electrons in dielectric is due to _________ |
A. | conduction |
B. | potential difference |
C. | breakdown |
D. | resistance |
Answer» D. resistance | |
95. |
m, calculate the dielectric strength. |
A. | 2mv/m |
B. | 4mv/m |
C. | 6mv/m |
D. | 8mv/m |
Answer» B. 4mv/m | |
96. |
The unit for dielectric strength is ____________ |
A. | v/m2 |
B. | mv/m2 |
C. | mv/m |
D. | vm |
Answer» D. vm | |
97. |
kV. Find „a‟. |
A. | 10mm |
B. | 100mm |
C. | 1000m |
D. | 1000cm |
Answer» E. | |
98. |
kV. |
A. | 350n |
B. | 0.035kn |
C. | 0.035n |
D. | 3.35kn |
Answer» D. 3.35kn | |
99. |
in air. |
A. | 1.41 |
B. | 3.5 |
C. | 2.2 |
D. | 1.73 |
Answer» E. | |
100. |
units and E = 8 units. |
A. | 1.77 |
B. | 2.25 |
C. | 36 |
D. | 144 |
Answer» D. 144 | |