Question

A bar magnet of length 10 cm is placed in the magnetic meridian with it's north pole pointing the geographical north . A neutral point is obtained at a distance of 12 cm from the centre of magnet . Find the magnetic moment of the magnet ,if bh =0.34g

Answer 1

ANSWER:

The magnetic moment, m = 13 A/m

EXPLANATION:

To find the magnetic moment of the bar magnet which is denoted by, m

We take the formula of magnetic field produced by a bar magnet, let us take the magnetic field of the Bar Magnet as, B

$B=\frac{\mu_{o} m}{4 \pi(d+l)^{2}}$

The magnetic field, B = 0.34G, converting the value of magnetic field B into Tesla, we get the value of B, as 0.000027 T

Now putting the values in the formula$B=\frac{\mu_{o} m}{4 \pi(d+l)^{2}}$ we get

0.000027=$\frac{4 \pi 10^{-7} \mathrm{m}}{4 \pi(0.12+0.10)^{2}}$

$\frac{27 \times(0.22)^{2}}{10^{-1}}=m$

$\frac{27 \times 4.84 \times 10^{-2}}{10^{-1}}=m$

Therefore, the magnetic moment of the bar magnet is m = 13 A/m