# Objective Type Question or MCQ of Electrical Circuits and Magnetic Fields page-8

106. The relative permeability of paramagnetic substance is

a) Unity
b) Slightly more than unity
c) Zero
d) Less than unity

Ans: (b)

107. The relative permeability of ferromagnetic material may have a value of several hundred or even several thousand

a) True
b) False

Ans: (a)

108. If A is the vector which of the following statements is true?

a) Div curl A = A
b) Div curl A = curl A
c) Div curl A = 0
d) Div curl A = curl div A

Ans: (c)

109. Which of the following statements is true?

a) The magnetomotive force around a closed path is equal to the conduction current plus electric displacement through any surface bounded by the path
b) The electromotive force around a closed path is equal to the time derivative of the electric displacement through any surface bounded by the path
c) The total electric displacement through the surface enclosing a volume is not equal to total charge within the volume
d) The net magnetic flux emerging through any closed surface is zero

Ans: (d)

110.Voltage across the resistance in R-L-C series circuit at resonance frequency is

a) Much higher than applied voltage
b) Much less than applied voltage
c) Function of value of inductance
d) Function of L/C ratio
e) Equal to applied voltage

Ans: (e)

111. A horseshoe magnet is head vertical with its ends resting on a horizontal board. The plane passing through its poles (assumed to lie at its ends) is in magnetic meridian. If N-pole of the magnet is towards magnetic south of the earth, the neutral point will lie

a) Within the poles of shoe magnet
b) At points along the axial line of the magnet
c) At point along the equatorial line of the magnet
d) At points not lying exactly on the horizontal board

Ans: (c)

112. A horseshoe magnet is far removed from magnetic substance. The magnetic potential will be zero at a point

a) Lying on its axial line
b) Lying on the centre of the line joining the two poles
c) Lying anywhere on its equatorial line
d) On the centre of the magnet

Ans: (c)

113. Three capacitors each of the capacity C are given. The resultant capacity 2C/3 can be obtained by using them

a) All in parallel
b) All in series
c) Two in series and third in parallel across this combination
d) Two in parallel and third in series with this combination

Ans: (d)

114. Two spheres of radii 10 and 20 cm have charges 100 and 200 e.s.u respectively. These are joined by a fine wire. The loss of energy will be

a) 1/2 × (10 × 20)/(10 +10) (200 + 100)2 ergs
b) 1/2 × (10+20)/(10×20) (200 – 100 ) ergs
c) 1/2 × (200 - 100)2 ergs
d) Zero

Ans: (d)

115. What will be the frequency of the following wave

a) 10 KHz
b) 5 KHz
c) 100 KHz
d) 150 KHz

Ans: (c)

116.If the pulse repetition of a square wave is 60 microseconds, the pulse repetition rate will be

a) 5 KHz
b) 16 KHz
c) 10 KHz
d) 15 MHz
e) 15 Hz

Ans: (b)

117. Using the following figure, find the capacitor discharge voltage when the switch is first placed in position A for 4.7 × 10-3 seconds, and then when the switch is placed in position B for 4.7 × 10-3 seconds. Assume that the initial charge on the capacitor is zero.

a) 9.45 volts
b) 15 volts
c) 3.5 volts
d) 6 volts

Ans: (c)

118. The Ohm’s law states that

a) V is proportional to I
b) I is proportional to V
c) V is proportional to IR
d) V is proportional to R

Ans: (a)

119. The electromagnetic radiation can only be emitted or absorbed by a matter in small discrete unity is called

a) Proton
b) Electron
c) Photon
d) Neutron

Ans: (c)

120. If the peak voltage of a wave is 15 V and pulse repetition time is 60 microseconds, with will be the average value of voltage?

a) 10 volts
b) 5 volts approximately
c) 15 volts
d) 7 volts

Ans: (b)

## Recent Post Multiple Choice Question (MCQ) of Transmission and Distribution page-3:21. ACSR conductor implies A) Anodized Core Smooth Run B) Anode current sinusoidally run C) Aluminium conductor steel reinforced D) All conductors surface treated and realigned.Read more... Multiple Choice Question (MCQ) of Transmission and Distribution page-2:11. In overhead transmission lines the effect of capacitance can be neglected when the length of line is less than A) 80 km B) 100 km C) 160 km D) 200 km.Read more... Multiple Choice Question (MCQ) of Transmission and Distribution page-1:1. Which of the following is not the transmission voltage in India ? A) 400 kV B) 264 kV C) 132 kV D) 66 kV.Read more...