Question

The intensity of magnetization of a bar magnet is $50\times {10}^{4}A{m}^{-1}$. The magnetic length and the area of cross section of the magnet are 12 cm and 1 $c{m}^2$ respectively The magnitude of magnetic moment of this bar magnet is (in SI unit)

• A. 0.6
• B. 1.3
• C. 1.24
• D. 2.4

Answer 1

The correct option is A 0.6

Intensity of magnetization $I=\frac{M}{V}$

where $M$ is the magnetic moment of the bar magnet

and $V$ is the volume of the magnet.

Hence $M=IV=5.0\times {10}^{4}A{m}^{-1}\times (0.12\times 1\times {10}^{-4}{m}^3)$

$=0.6A{m}^2$