A thin ring of radius `R` metre has charge `q` coulomb uniformly spread on it. The ring rotates about its axis with a constant frequency of `f` revolution/s. The value of magnetic induction in `Wb m^(-2)` at the centre of the ring is

Options

A. `(mu_0qf)/(2pi R)`
B. `(mu_0 q)/(2pi fR)`
C. `(mu_0 q)/(2fR)`
D. `(mu_0 qf)/(2R)`

Answer

D

Explanation

`B = (mu_0i)/(2R) = (mu_0 )/(2R) xx q/T = (mu_0)/(2R) qf`