question_answer

A square loop is carrying a steady current I and the magnitude of its magnetic dipole moment is m. If this square loop is changed to a circular loop and it carries the same current, the magnitude of the magnetic dipole moment of circular loop will be : [JEE Main 10-4-2019 Afternoon]

A) \[\frac{3m}{\pi }\]

B) \[\frac{4m}{\pi }\]

C) \[\frac{2m}{\pi }\]

D) \[\frac{m}{\pi }\]

Correct Answer: B

Solution :

[b] here a = side of square

Now,

For circular loop