Question

A rod of length L, along East west direction is dropped from a height H. If B be the magnetic field due to earth at that place and angle of dip is $\theta$ , then what is the magnitude of induced emf across two ends of the rod when the rod reaches the earth.

Answer 1

Given,

$Length=L,Height=H$ and MAgnetic field $B$ Angle -=$\theta$

The horizontal component of the magnetic field is $Bcos\theta$

Since $Bcos\theta$ is the net field that will account for the induced emf in the rod,

So, the velocity of the rod after fallina a distance

$\mu =\sqrt{2gH}$

So induced emf $=Bsin\theta \times L\times \sqrt{2gH}$