Question:
The magnetic moment of an iron bar is M. It is now bent in such a way that it forms an arc section of a circle subtending an angle of 60° at the centre. The magnetic moment of this arc section is
The magnetic moment of an iron bar is M. It is now bent in such a way that it forms an arc section of a circle subtending an angle of 60° at the centre. The magnetic moment of this arc section is
Updated On: Feb 11, 2026
- $\frac{3M}{\pi}$
- $\frac{4M}{\pi}$
- $\frac{M}{\pi}$
- $\frac{2M}{\pi}$
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The Correct Option is A
Solution and Explanation
R0 = L
$\frac{R\pi}{3}$ = L
R = $\frac{3L}{\pi}$
M' = m(2R) sin 30°
= m(2)$\frac{3L}{\pi}$ × $\frac{1}{2}$ = $\frac{3}{\pi}$mL = $\frac{3M}{\pi}$
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