Question 242 of 276

A straight magnetic strip has a magnetic moment of $44 \mathrm{Am}^2$. If the strip is bent in a semicircular shape, its magnetic moment will be _______ $\mathrm{Am}^2$.
(given $\pi=\frac{22}{7}$ )

Your answerCheck answer

Show answer and solution▾

Answer: 28

Magnetic moment of straight wire $=\mathrm{mx} \ell=44$

Magnetic moment of arc
$\begin{aligned}& =\mathrm{m} \times 2 \mathrm{r} \\& =\mathrm{m} \times \frac{2 \ell}{\pi} \\& =\frac{44 \times 2}{\pi}=\frac{88}{\pi}=28\end{aligned}$