CBSE Class 12 · 2024 · Electromagnetic InductionMultiple Choice

A coil of area of cross-section

0.5 m^{2}

is placed in a magnetic field acting normally to its plane. The field varies as

B = 0.5 t^{2} + 2 t

, where

B

is in tesla and

t

in seconds. The emf induced in the coil at

t = 1 s

(A)0.5 V
(B)1.0 V
(C)1.5 V✓ Correct
(D)3.0 V

Answer: (C)

Solution

The flux is

ϕ = B A = (0.5 t^{2} + 2 t) (0.5)

.
The induced emf has magnitude

∣ ε ∣ = \frac{d ϕ}{d t} = A \frac{d B}{d t} = 0.5 (t + 2)

t = 1 s

∣ ε ∣ = 0.5 (1 + 2)

∣ ε ∣ = 1.5 V

CBSE Class 12 Board · 2024 · Single correct option

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