Q80 / 90 · JEE Main 2024 (29 Jan Shift 2) · Physics

A horizontal straight wire $5 m$ long extending from east to west falling freely at right angle to horizontal component of earth's magnetic field $0.60 \times 10^{- 4} Wb m^{- 2}$ . The instantaneous value of emf induced in the wire when its velocity is $10 m s^{- 1}$ is _______ $\times 10^{- 3} V$ .

Correct answer: 3

Solution

Horizontal component of earth's magnetic field,

$B_{H} = 0.60 \times 10^{- 4} Wb m^{- 2}$ .

Induced $emf e = B_{H} v ℓ$

$= 0.60 \times 10^{- 4} \times 10 \times 5$

$= 3 \times 10^{- 3} V$

Hence, the correct answer is 3.