Q. A metal disc of radius $100cm$ is rotated at a constant angular speed of $60rads^{- 1}$ in a plane at right angles to an external field of magnetic induction $0.05Wbm^{- 2}$ . The emf induced between the centre and a point on the rim will be
NTA AbhyasNTA Abhyas 2022
Solution:
Emf induced between the centre and a point on the rim due to a rotating disc is given by, $e=\frac{1}{2}B\omega R^{2}$
where, $B=$ External field of a magnetic induction,
$\omega =$ Angular speed of rotation and
$R=$ Radius of disc.
So, $e=\frac{1}{2}\left(0 . 05\right)\left(60\right)\left(1\right)^{2}=1.5V$
where, $B=$ External field of a magnetic induction,
$\omega =$ Angular speed of rotation and
$R=$ Radius of disc.
So, $e=\frac{1}{2}\left(0 . 05\right)\left(60\right)\left(1\right)^{2}=1.5V$