A metal disc of radius 200 cm is rotated at a constant angular speed of `60rad s^(-1)` in a plane at right angles to an external field of magnetic induction `0.05 Wb m^(-2)`. Find the e.m.f. induced between the centre and a point on the rim.

Options

A. 12 V
B. 8 V
C. 2V
D. 6 V

Answer

D

Explanation

`e = BAv = B.A xx (omega)/(2pi) = B xx pi R^2 xx omega/(2pi)`
`e = 1/2 xx 0.05 xx (2)^2 xx 60 = 6 "volt"`