Question

A copper rod of length 2 m fixed at one end is rotating with angular velocity 300 rad s⁻¹ about the fixed end in a uniform magnetic field of intensity 0.4Tesla. Find the induced e.m.f. between the centre of circle and far end of the rod.

Answer 1

length of copper rod , L= 2m

angular velocity, $\omega$ = 300 rad/s

uniform magnetic field , B = 0.4T

use formula, $\xi_{in}=\frac{1}{2}B\omega L^2$

where $\xi_{in}$ denotes induced emf.

now, $\xi_{in}$ = 1/2 × 0.4 × 300 × (2)²

= 1/2 × 0.4 × 300 × 4

= 0.4 × 300 × 2

= 0.8 × 300 = 240 V

hence, induced emf between the centre of the circle and far end of the rod = 240V