Question

A bar magnet of magnetic moment `3.0 A-m^(2)` is placed in a uniform magnetic induction field of `2xx10^(-5)T`. If each pole of the magnet experiences a force of `6xx10^(-4)N`, the length of the magnet is
A. `0.5 m`
B. `0.3 m`
C. `0.2 m`
D. `0.1 m`

Answer 1

Correct Answer - D
`F= mB rArr F=M/LxxB`
`implies 6xx10^(-4)=3/Lxx2xx10^(-5) implies L=0.1 m`.