Question

The moment of a magnet ($15cm\times 2cm\times 1cm$) is $1.2A{m}^2$. What is its intensity of magnetisation?

• A. $4\times {10}^{4}A{m}^{-1}$
• B. $2\times {10}^{4}A{m}^{-1}$
• C. ${10}^{4}A{m}^{-1}$
• D. none of these

Answer 1

Answer: (A)

$4\times {10}^{4}A{m}^{-1}$

Intensity of magnetisation,

$I_m=\frac{M}{V}$
$=\frac{1.2}{(15\times 2\times 1){10}^{-6}}$
$=4{\times 10}^{4}A{m}^{-1}$