The moment of a magnet is `1 muWb-m` and the force acting on each pole in a uniform magnetic field of strength 0.38 oersted is `1.024xx10^(-4) N`. Distance between the poles of the magnet is

Options

A. `1.56xx10^(-4)cm`
B. `0.37xx10^(-4)cm`
C. `2.34xx10^(-4)cm`
D. `1.17xx10^(-4)cm`

Answer

B

Explanation

Force acting on each pole, `F=mB`
`M=ml`
`implies m= M/l`
`implies l=(MB)/(F)`
`implies l=(1xx10^(-6)xx0.38xx10^(-4))/(1.024xx10^(-4))`
`therefore l=0.37xx10^(-4)cm`