A magnet of magnetic moment `20` C.G.S. units is freely suspended in a uniform magnetic field of intensity 0.3 C.G.S. units. The amount of work done in deflecting it by an angle of `30^(@)` in C.G.S. unit is

Options

A. 6
B. `3sqrt(3)`
C. `3(2-sqrt(3))`
D. 3

Answer

c

Explanation

Work done , `W=MB_(mu)(2-cos theta)`
`=20xx0.3(1-cos 30^(@))=6(1-(sqrt(3))/2)=3(2-sqrt(3))`