Current flows through uniform, square frames as shown in the figure. In which case is the magnetic field at the centre of the frame not zero?

Options

A.
B.
C.
D.

Answer

C

Explanation

In arrangement a , b, and , the field at the centre due to the currentss flowing in the squre frames is zero .The filds here due to the currents are in and out of the frames and they and they are equal in magnitude.