Question

A thin bar magnet of length $2l$ and breadth $2b$ pole strength $m$ and magnetic moment $M$ is divided into four equal parts with length and breadth of each part being half of original magnet. The magnetic moment of each part is

• A. $M/4$
• B. $M$
• C. $M/2$
• D. $2M$

Answer 1

The correct option is A $M/4$

As length of each part also becomes half, therefore magnetic moment

$M=$pole strength $\times$ length

$\Rightarrow \frac{1}{2}\times \frac{1}{2}=\frac{1}{4}th$

i.e., $M/4$