Electromagnetic Induction Class 12 MCQ: Class 12 Physics MCQ Questions and Answer. Students get here all Important MCQ on Electromagnetic Induction Class 12.
Electromagnetic Induction Class 12 MCQ with Answers:
Multiple choice questions.
1.) The emf produced in the conductor is called induced emf , and the current generated is called the induced current. This phenomenon is known as,
a) Electric induction
b) Magnetic induction
c) Electromagnetic induction
d) Current induction
Ans : c) Electromagnetic induction
2.) Fill in the blank.
The emf induced by the motion of a conductor across a magnetic field is called.
a) Induced current
b) Induced magnet
c) Motional emf
d) Motional current
Ans : c) Motional emf
3.) When a rod moves, a charge q within the rod also moves with the velocity v in the magnetic field B and E0 be the electric intensity then,
a)E0= qvB.
b)E0= vB
c) E0q=vB.
d) E0v=qB
Ans : b) E0 = vB
4.) Complete the formula.
If the angle between v and B is θ then magnitude of Motional emf is,
ε = -vBL______
a) sinθ.
b) cosα
c) cosθ.
d) cosecα
Ans : a)sinθ
5.) Complete the Farday’s law of induced emf of coil of N loops ,
ε = -N ______
a)∆Φ
b) ∆Φ/∆t
c) ∆t
d) ∆t / ∆Φ
Ans : b) ∆Φ/∆t
6.) Fill in the blank of “Farday’s law”
” The average emf induced in a conducting coil of N loops is equal to the negative of the rate at which the magnetic flux through the coil is changing with____”
a)electromagnet.
b) flux
c) time.
d) N loops
Ans : c) time
7.) Fill in the blank of lenz’s law
” The direction of the induced current is always so as to oppose the change which couses the ________”
a) electromagnet. b) flux
c) current. d) time
Ans : c) current
8.) The phenomenon in which a changing current in one coil induces an emf in another coil is called ,
a) Magnetic induction
b) Electric induction
c) Mutual induction
d) Current induction
Ans : c) Mutual induction
9.) M be the mutual induction and it is defined as the ratio of average emf induced in the secondary to the time rate of change of current in the primary coil.
M= εs/(∆Ip/____)
a)∆t.
b)∆Φ
c) Np.
d) ∆I
Ans : b) ∆t
10.) The SI unit of mutual inductance is
a)m.
b) sec
c) m.sec-1
d) m-1sec-1
Ans : a) m
11.) In below, which is the unit of mutual inductance.
a) watt.
b) henry
c) Ohm.
d) weber
Ans : b) henry
12.) The phenomenon in which a changing current in a coil induces on emf in itself is called.
a) Magnetic induction
b) Self induction
c) Mutual induction
d) Electric induction
Ans : b) Self induction
13.) Energy stored in an inductor, Um = ½×L____
a)I²
b)I
c)W.
d) ∆q
Ans : a) I²
14.) Energy density can be defined as the energy stored per unit volume inside the solenoid then
Um = ½(B²/___)
a)I.
b)I²
c) μ0
d) μ0²
Ans : c) μ0
15.) In alternating current genarator, the induced current in the coil is I = I0___(2πft)
a)sin.
b) cos
c) ε.
d) ε0
Ans : a) sin
16.) Which device is used to convertes electric energy into mechanical energy.
a)A.C generator.
b) Voltmeter
c) D.C motor.
d) Transformer
Ans : c) D.C motor
17.) The potential difference of back EMF effect in motors.
V = ε +______
a)IR.
b) I +R
c) (I-R).
d) I/R
Ans : a) IR
18.) Which device is used to change a given alternating emf into a larger or smaller alternating emf.
a)D.C motor.
b) Multimeter
c) A.C generator.
d) Transformer
Ans : d) Transformer
19.) In transformer Vp is primary voltage and Vs is secondary voltage , Ip is primary current whereas Is is secondary current then the relation between them is.
a) VsVp = IsIp
b) Vs/ Vp = Ip/ Is
c) Vs /Vp = Is/ Ip
d) VsIp = VpIp
Ans : b) Vs/ Vp = Ip/ Is
20.) The emf produced in a generator is
a) ε = NωABsin(ωt)
b) ε = Nωsin(ωAt)
c) ε = Nωtsin(ωA)
d) ε = Nωtsin(ωt)
Ans : a) ε = NωABsin(ωt)
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