Question

If a circular coil of $100$ turns and radius $10$cm carries a current of $1$A, find the magnetic dipole moment of the coil.

Answer 1

Number of turns in coil, $n=100$
Radius, $r=10cm=0.1m$
Current, $I=1A$
Magnetic dipole moment, $M=nIA=nI$$\pi r^2$ $=100\times 1\times \pi {0.1}^2$ $=4.14m^{2}A$