Q.

The magnetic potential energy, when a magnetic bar of magnetic moment m is placed perpendicular to the magnetic field B is          [2024]
 

1 -mB2  
2 zero  
3 -mB  
4 mB  

Ans.

(2)

The magnetic potential energy is given by

V=-m·B=-mBcosθ

when,    θ=90°;  V=-mBcos90°=0