Moving Charges And Magnetism

A thin ring of radius '\(R\)' meter 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 \(\mathrm{Wb} \mathrm{m}^{-2}\) at the center of the ring is
(\(\mu_0=\) Permeability of free space)