Given below are two statements: Statement I: When a straight bar...

Statement I is correct: Let the initial length of the bar magnet be $L$ and its pole strength be $m$. Its magnetic moment is $M = m L$. When bent into a semicircle of radius $R$, the arc length is $L = \pi R$, which gives $R = \dfrac{L}{\pi}$. The new effective magnetic length is the shortest distance between the poles, which is the diameter $2R = \dfrac{2L}{\pi}$. The new magnetic moment is $M' = m \left( \dfrac{2L}{\pi} \right) = \dfrac{2M}{\pi}$.

Statement II is incorrect: The pole strength of a bar magnet depends only on the nature of the material and its cross-sectional area. It does not change when the magnet is bent into a curved shape.

Answer: Statement I is correct but Statement II is incorrect