A regular polygon of sides is formed by bending a wire of total length that carries a…

PHYSICS · Multi-part · CBSE · Physics · Moving Charges and Magnetism · Moving Charges and Magnetism

Problem

A regular polygon of

n

sides is formed by bending a wire of total length

2\pi r

that carries a current

I

. (a) Find the magnetic field

B

at the centre of the polygon. (b) By letting

n\to\infty

, deduce the expression for the magnetic field at the centre of a circular coil.