Electromagnetism Class 12 MCQ: Class 12 Physics MCQ Questions and Answer. Students get here all Important MCQ on Electromagnetism Class 12.
Electromagnetism Class 12 MCQ with Answers:
Multiple choice questions
1.) Fill in the blank.
If the wire is grasped in first of ______ with the thumb pointing in the direction of the current, the fingers of the hand will circle the wire in the direction of the magnetic field.
a) right hand.
b) left hand
c) right thumb.
d) left thumb
Ans : a) right hand
2.) Force on a current carrying conductor in a uniform magnetic field.
F = ILB_______
a) sinα.
b) cosα
c) tanα.
d) secα
Ans : a) sinα
3.) One Tesla can be expressed as.
a)1NA-1
b)1NA-1m-1
c) 1NAm-1
d) 1NmA-1
Ans : b) 1NA-1m-1
4.) The magnetic flux ΦB through a plane element of area A in a uniform magnetic field B is given by dot product of B and A .
ΦB = B.A______
a) sinθ.
b) cosθ
c) tanθ.
d) secθ
Ans : b) cosθ
5.) The unit of magnetic flux can be expressed as.
a) watt.
b) Joules
c) weber.
d) Coulomb
Ans : c) weber
6.) The unit of flux density can be expressed as.
a)Wb.m
b)Wb.m-2
c)Wbm-1
d) Wb.m²
Ans : b)Wbm-2
7.) The unit of magnetic field strength can be expressed as.
a) watt.
b) weber
c) ohm.
d) tesla
Ans : d) tesla
8.) In SI units the value of permeability of free space μ0 can be expressed as
a) 4π×10-6 WbA-1m-1
b) 4π×10-7 WbA-1m-1
c) 4π×10-8 WbA-1m-1
d) 4π×10-9 WbA-1m-1
Ans: b) 4π×10-7 WbA-1m-1
9.) The magnetic field of the solenoid can be expressed as.
a) B = μ0nl
b) B = μ0Il
c) B = μ0n2l
d) B = μ0nl
Ans : d) B = μ0nI
10.) The force experienced by a single charge carrier moving with velocity V in magnetic field.
a) F = q ( V×B)
b) F = q ( V+B)
c) F = V ( q+B)
d) F = B ( q+V)
Ans : a) F = q ( V×B)
11.) When an electric charge q is placed in an electric field E, it experiences a force F parallel to electric field. It is given by.
a)F=qE.
b) q=FE
c) E = Fq.
d) F= q/E
Ans : a) F = qE
12.) F = qE + q(V×B), This force F is known as.
a) Coulomb’s force.
b) Lorentz force
c) Weber’s force.
d) Newton force
Ans : b) Lorentz force.
13.) Complete the formula of determination of e/m of an electron.
e/m =________
a)2V/Br2.
b) 2V²/B²r²
c)2V/B²r2.
d)2V/B²r
Ans : c) 2V / B²r²
14.) CRO used for displaying the waveform of a given______
a) Energy.
b) Voltage
c) Power.
d) Resistance
Ans : b) Voltage
15.) In CRO, the Y-axis calibrated as
a) volt
b) resistance
c) time.
d) power
Ans : a)volt
16.) In CRO, X-axis calibrated as
a)volt.
b) resistance
c) time.
d) power
Ans : c) time
17.) Fill in the blank.
Torque = Force × _____
a) Distance between the arms
b) Moment arm of the couple
c) Area of the arms
d) Length of the arms
Ans : b) Moment arm of the couple
18.) Torque on a current carrying coil placed in a Magnetic field.
= IBA______
a)sinα.
b) cosα
c) tanα.
d) cosecα
Ans : b) cosα
19.) Which device is used to detect small current deflection.
a) Galvanometer.
b) Ammeter
c) Rheostat.
d) Voltmeter
Ans : a) Galvanometer
20.) Complete the formula.
Current passing through the coil, I = (c/BAN)×______
a)cosθ.
b) θ
c) sinθ.
d) θ-1
Ans : b) θ
21.) From Ohm’s law the potential difference Vg which causes a current Ig to pass through the galvanometer is given by.
a) Vg = IgRg. b) Ig=VgRg
c) Rg=Vg Ig. d) Vg = Ig/Rg
Ans : a) Vg = IgRg
22.) The formula for sheet resistance R of the galvanometer can be expressed as.
a)(I-Ig/Ig)/Rg.
b) (Ig/I-Ig)/Rg
c) (I+Ig/Ig)/Rg.
d) (Ig/I+Ig)/Rg
Ans : b) (Ig/I-Ig)/Rg
23.) High resistance Rh can be expressed as
a)(V/Ig)-Rg
b) (V/Rg)-Ig
c) (Ig/V)-Rg.
d) (Rg/V)-Ig
Ans: a) (V/Ig)-Rg
24.) Which device is used for rapid measurement of resistance.
a) ammeter.
b) voltmeter
c) ohmmeter.
d) galvanometer
Ans : c) ohmmeter
25.) Which device is used to measure current in ampere, potential difference in volts and resistance in ohms.
a) Ammeter.
b) Voltmeter
c) Ohmmeter.
d) Avometer
Ans: d) Avometer
26.) Fill in the blank.
A galvanometer is connected into a ______ by connecting a high resistance in series.
a) Ammeter.
b) Voltmeter
c) Rheostat.
d) Resistor
Ans : b) Voltmeter
27.) A_____is converted into an ammeter by properly shunting it.
a) Ammeter.
b) Galvanometer
c) Resistance box.
d) Rheostat
Ans : b) Galvanometer
28.) What shunt resistance must be connected across a galvanometer of 40Ω resistance which gives full scale deflection with 3.2 mA current, so as to converte it into an ammeter of range 9.7A?
a)0.132
b) 0.0132
c) 0.00132
d) 1.32
Ans : b) 0.0132
For more updates follow our net explanations homepage