Question

A wire is bend into coil in n turns of ame radius if current i is flowing in clockwise direction find the magnitude and direction at its centre

Answer 1

The direction of magnetic field is normal to plane of coil in downward direction.

Answer 2

Let the radius of the coil be r

As tge wire is bent round in the form of coil having N turns.

N * circumference of coil = lemgle of wire

L = 2 \pi r* N

Hence

r = L/ 2\piN

Now magnetic field is given by

B = \large \muo* N I/ 2r

B = \large \muo *\large \pi* N² I/L