Two concentric coil X and Y of radii `16cm` and `10cm` respectively lie in the same vertical plane containing the north-south direction. Coil X has 20 turns and carries a current of 16A, coil Y has 25 turns and carries a current of 18A. The sense of current in X is anti-clockwise and in Y, clockwise, for an observer looking at the coil facing west, Figure. Give the magnitude and direction of the net magnetic field due to the coils at their centre.

Explanation

`5pi xx 10^(-4) T = 1.6 xx 10^(-3) ` T towards west .