A metallic conductor of length 1 m rotates in a vertical plane parallel to east-west direction about one of its end with angular velocity $5 \mathrm{rad} / \mathrm{s}$. If the horizontal component of earth's magnetic field is $0.2 \times 10^{-4} \mathrm{~T}$, then emf induced between the two ends of the conductor is :

JEE Main · 2022 · 26 Jun 2022 · Shift 2 · Electromagnetic Induction

A metallic conductor of length 1 m rotates in a vertical plane parallel to east-west direction about one of its end with angular velocity

5 rad / s

. If the horizontal component of earth's magnetic field is

0.2 \times 1 0^{- 4} T

, then emf induced between the two ends of the conductor is :

(A) $5 μ V$
(B) $50 μ V$ ✓ Correct
(C)5 mV
(D)50 mV

Answer: (B)

Solution

For a rod rotating about one end in a magnetic field, the induced emf is given by

ε = \frac{1}{2} B ω l^{2}

. Substituting the values:

ε = \frac{1}{2} \times 0.2 \times 1 0^{- 4} \times 5 \times 1^{2} = 0.5 \times 1 0^{- 4} V = 50 μ V

JEE Main · 2022 · 26 Jun 2022 · Shift 2 · Single correct option

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