Question

A long bar magnet has a pole strength of 10 Am. Find the magnetic field at a point on the axis of the magnet distance of 5 cm from the north pole of the magnet.

Answer 1

Here M = 10 A.m,

d= 5 cm = 0.05 m

B= $\frac{{\mu }_0}{4\pi }\frac{M}{r^2}$

= $\frac{{10}^{-7}\times 10}{(5\times {10}^{-2}{)}^2}=\frac{{10}^{-6}}{25\times {10}^{-4}}$

= $\frac{{10}^{-2}}{25}=4\times {10}^{-4}$ Telsa.