A metal wire of length $2500 \mathrm{~m}$ is kept in east-west direction, at a certain height from the…

A metal wire of length $2500 \mathrm{~m}$ is kept in east-west direction, at a certain height from the ground. If it falls freely on the ground, then the current induced in the wire when its speed is $10 \mathrm{~m} / \mathrm{s}$ is (Resistance of wire $=25 \Omega, g=10 \mathrm{~m} / \mathrm{s}^2$ and Earth's horizontal component of magnetic field $\mathrm{B}_{\mathrm{H}}=2 \times 10^{-5} \mathrm{~T}$ )
  1. $0.2 \mathrm{~A}$
  2. $0.02 \mathrm{~A}$
  3. $0.01 \mathrm{~A}$
  4. $2 \mathrm{~A}$

Solution

Emf induced, e $=\mathrm{B}_{\mathrm{H}} l$ $\begin{aligned} & =2 \times 10^{-5} \times 10 \times 2500=0.5 \mathrm{~V} \\ & \mathrm{I}=\mathrm{e} / \mathrm{R}=0.5 / 25=0.02 \mathrm{~A} \end{aligned}$

Asked in: MHT CET 2021 (20 Sep Shift 1)

Practice more Electromagnetic Induction questions on Aicharya