A conducting ring of radius 1 m kept in a uniform magnetic field B of 0.01 T, rotates uniformly with an angular velocity 100 `rads ^(-1)` with its axis of rotation perpendicular to B. The maximum induced emf in it is

Options

A. `1.5pi V`
B. `pi V`
C. `2 piV`
D. `0.5 pi V`

Answer

B

Explanation

By magnetic induction
`B = (phi)/(A)`
`phi = BA = pi r ^(2) B `
`phi = pi xx (1) ^(2) xx 0.01 = 0.01 pi`
`(d phi )/( dt) = B A omega cos omega t `
`tau _(max) = BA omega `
`= 0.01 pi xx 100 = pi ` volt