Question

The magnetic potential at a point distant 10 cm from the middle point of a magnetic dipole on a line inclined at an angle of`60^(@)` with the axis is 3 e.m.u Then the magnetic moment of magnet is
A. 600 ab amp`cm^(2)`
B. 300 ab amp `cm^(2)`
C. 150 ab amp`cm^(2)`
D. 300 `sqrt(3)` ab amo `cm^(2)`

Answer 1

Correct Answer - A
`V=(mu_(0))/(4pi)(Mcostheta)/(r^(2))`
`V=(mcostheta)/(r^(2)) "in" C.G.S. system`
`M=(Vr^(2))/(costheta)=(3xx100)/(cos60)=600 abA cm^(2)`