At the centre of a fixed large circular coil of radius R, a much smaller circular coil of radius r is placed. The two coils are concentric and are in…

At the centre of a fixed large circular coil of radius R , a much smaller circular coil of radius r is placed. The two coils are concentric and are in the same plane. The larger coil carries a current I. The smaller coil is set to rotate with a constant angular velocity $\displaystyle \omega$ about an axis along their common diameter. Calculate the emf induced in the smaller coil after a time t of its start of rotation.