The magnetised wire of moment M and length l is bent in the form of semicircle of radius r. Then its magnetic moment is

Question

The magnetised wire of moment M and length l is bent in the form of semicircle of radius r. Then its magnetic moment is (A) (2M/π) (B) 2M (C) (M/π) (D) zero

Tardigrade Admin · Accepted Answer

Use the formula of the magnetic moment of a bar magnet. Step 1: Write the expression of the initial magnetic moment.

We have length =1, Magnetic moment = M Therefore M = ml ; where m = pole strength Step 2: Calculate the final magnetic moment.

Now wire of length 1 changes to semicircle (Let radius is r ) therefore 1=π r ⇒ r =(1/π) Now new magnetic moment M'=M × 2 r=(2 m l/π)=(M/π)

Q. The magnetised wire of moment $M$ and length $l$ is bent in the form of semicircle of radius $r$ . Then its magnetic moment is

$\frac{2 M}{π}$

$2 M$

$\frac{M}{π}$

zero

Q. The magnetised wire of moment M and length l is bent in the form of semicircle of radius r. Then its magnetic moment is

π2M​

2M

πM​

zero

Q. The magnetised wire of moment $M$ and length $l$ is bent in the form of semicircle of radius $r$ . Then its magnetic moment is

$\frac{2 M}{π}$

$2 M$

$\frac{M}{π}$