Question

The magnetic moment of a magnet of dimensions $(10\text{cm}\times 4\text{cm}\times 1\text{cm})$ is $4{\text{A-m}}^2$. Its intensity of magnetisation is :

• A. ${10}^3\text{A/m}$
• B. ${10}^2\text{A/m}$
• C. ${10}^5\text{A/m}$
• D. ${10}^4\text{A/m}$

Answer 1

The correct option is C ${10}^5\text{A/m}$

$\left|I\right|=\frac{\left|M\right|}{V}$

$\left|M\right|\to$ Magnetic moment

$V\to$ Volume

$\left|I\right|=\frac{4}{10\times {10}^{-2}\times 4\times {10}^{-2}\times {10}^{-2}}$

$\left|I\right|={10}^5\text{A/m}$

Hence, option $\left(C\right)$ is the correct answer.