Write equation of magnetic field on axis from centre which have distance equal to radius.

An electron revolves around nucleus with rotational frequency $'f'$ in circular orbit, due to this magnetic induction produced at nucleus position is $'B'$ then radius of circular orbit is directly proportional to

The magnetic field near a current carrying conductor is given by

A current $I$ flows in an infinitely long wire with cross-section in the form of a semicircular ring of radius $R$ . The magnitude of the magnetic induction along its axis is

Tesla is the unit of

The magnitude of magnetic induction at mid-point $O$ due to current arrangement as shown in Fig will be