An infinite long solenoid having n turns per unit length is shown in figure. The magnetic field at P, when a current I is flowing through it would be

A coil having N turns carry a current I as shown in the figure. The magnetic field intensity at point P is

A coil having N turns carry a current I as shown in the figure. The magnetic field intensity at point P is

A toroid has number of turns per unit length n , current i , then the magnetic field is

A long solenoid has n turns per metre and current IA is flowing through it. The magnetic field induciton at the ends of the solenoid is

The magnetic field on the axis of a long solenoid having n turns per unit length and carrying a current is

A very long straight solenoid has a cross section radius R . A number of turns per unit length is equal to n . Find the magnetic induction at the centre of the coil when a current I flows thougth it.