Find the magnetic potential at a point and distance of 1m from the centre of short magnetic dipole of moment `100 Am^(2)`, if line joining point to the centre of dipole makes an angle `60^(@)C` with the dipole moment vector.

Options

A. `10xx10^(-6)J//Am`
B. `2.5xx10^(-6)J//Am`
C. `5xx10^(-6)J//Am`
D. `0.5xx10^(-6)J//Am`

Answer

C

Explanation

Magnetic potential
`V=(mu_(0))/(4pi)xx(M cos theta)/(r^(2))`
`therefore V=10^(-7)xx(100 xx cos 60^(@))/(1^(2))`
`V= 10^(-7)xx10^(2)xx(1)/(2)=0.5 xx10^(-5)`
`=5xx10^(-6)J` Am