Electromagnetic Induction  MCQs

MCQs of Electromagnetic Induction

Showing 11 to 20 out of 113 Questions
11.
A wheel with 10 metallic spokes each 0.5 m long rotated with a speed of 120 rpm in a plane normal to the horizontal component of earth's magnetic field Bh at a place. If Bh = 0.4 G at the place, what is the induced emf between the axle and the rim of the wheel ? (1 G = 10-4 T)
(a) 0 V
(b) 0.628 mV
(c) 0.628 µV
(d) 62.8 µV
Answer:

Option (d)

12.
A rod of 5 cm length is moving perpendicular to uniform magnetic field of intensity 2 × 10-4 Wbm-2 . If the acceleration of rod is 2 ms-2, the rate of increase of the induced emf is _____ .
(a) 20 × 10-4 Vs-2
(b) 20 × 10-4 V
(c) 20 × 10-4 Vs
(d) 20 × 10-4 Vs-1
Answer:

Option (d)

13.
Current of 2A passing through a coil of 100 turns gives rise to a magnetic flux of  5 × 10-3 Wb per turn. The magnetic energy associated with coil is _____ .
(a) 5 × 10-3 J
(b) 0.5 × 10-3 J
(c) 5 J
(d) 0.5 J
Answer:

Option (d)

14.
The flux linked per each turn of a coil of N turns changes from Φ1 to Φ2. If the total resistance of the circuit including the coil is R, the induced charge in the coil.
(a) NΦ2 - Φ1t
(b) NΦ2 - Φ1R
(c) NΦ2 - Φ1Rt
(d) NΦ2 - Φ1
Answer:

Option (b)

15.
In AC generator, induced emf is zero at time t = 0. The induced emf at time π2ω is _____ .
(a) +2 Vm
(b) +1.5 Vm
(c) +3.5 V
(d) +1 Vm
Answer:

Option (a)

16.
A thin circular ring of area A is held perpendicular to a uniform field of induction B. A small cut is made in the ring and a galvanometer is connected across the ends such that the total resistance of the circuit is R. When the ring is suddenly squeezed to zero area, the charge flowing through the galvanometer is,
(a) BRA
(b) ABR
(c) ABR
(d) B2AR
Answer:

Option (b)

17.
A thin circular ring of area A is held perpendicular to a uniform field of induction B. A small cut is made in the ring and a galvanometer is connected across the ends such that the total resistance of the circuit is R. When the ring is suddenly squeezes to zero area, the charge flowing through the galvanometer is _____
(a) BRA
(b) ABR
(c) ABR
(d) B2AR
Answer:

Option (b)

18.
Current of 2A passing through a coil of 100 turns gives rise to a magnetic flux of 5 × 10-3 WB per turn. The magnetic energy associated with coil is _____
(a) 5 × 10-3 J
(b) 0.5 × 10-3 J
(c) 5 J
(d) 0.5 J
Answer:

Option (d)

19.
A coil of surface area 100 cm2 having 50 turns is held perpendicular to the magnetic field of intensity 0.02 Wbm-2. The resistance of the coil is 2 Ω. If it is removed from the magnetic field in 1 s, the induced charge in the coil is _____.
(a) 5 C
(b) 0.5 C
(c) 0.05 C
(d) 0.005 C
Answer:

Option (d)

20.
The mutual inductance of a system of two coils is 5 mH. The current in the first coil varies according to the equation I = I0 sin ωt, where I0 = 10 A and ω = 100π rad s-1 . The value of the maximum induced emf in the second coil is _____.
(a) π V
(b) π V
(c) π V
(d) π V
Answer:

Option (b)

Showing 11 to 20 out of 113 Questions