Question

A wire of length L is bent around in the form of a coil having N turns of same radius . If a steady current I flows through it in a clockwise direction, find the magnitude and direction of the magnetic field produced at its centre.

Answer 1

If r is the radius of the coil formed, then
`L=2pirN` or `r=(L)/(2piN)`
Magnetic field induction at the centre of the coil due to current I is
`B=(mu_0)/(4pi)(2piNI)/(r)=(mu_0)/(4pi)(2piNI)/((L//2piN))=(mu_0piN^2L)/(L)`
As the current flows clockwise through the coil the directin of the magnetic field according to Right Hand Rule, will be perpendicular to the plane of coil inwards.