Q.

An iron bar of length L has magnetic moment M. It is bent at the middle of its length such that the two arms make an angle 60° with each other. The magnetic moment of this new magnet is           [2024]
 

1 M  
2 M2  
3 2 M  
4 M3  

Ans.

(2)

Mnet=(M2)2+(M2)2+2M2·M2cos120°

Mnet=M24×2-M24=M24=M2