A 2 m long metallic rod rotates with an angular frequency `200" rod "s^(-1)` about on axis normal to the rod passing through its one end. The other end of the rod is in contact with a circular metallic ring. A constant megnetic field of 0.5 T parallel to axis exises everywhere. The emf developed between the centre and the ring is

Options

A. 50V
B. 100V
C. 150V
D. 0V

Answer

B

Explanation

The emf developed across the ends of the rod is `epsi = 1/2 B omega l^2`
Here `B = 0.5T , omega = 400 rad//s , l = 1.0 m`
`therefore epsi = 1/2 xx 0.5 xx 400 xx (1.0)^2= 100V`