A metal disc of radius 200 cm is rotated at a constant angular speed of `rad 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.

Explanation

Here, `r = 200 cm = 2 m, omega = 60 rad//s`.
`B = 0.05 Wb m^(-2)`
`e = BA v = BA ((omega)/(2 p)) = B (pi r^(2)) ((omega)/(2 pi))`
`e = (1)/(2) B r^(2) omega = (1)/(2) xx 0.05 (2)^(2) xx 60 = 6 V`