The distance between the poles of a horse shoe magnet is 0.1 m and its pole strength is 0.01 amp-m. The induction of magnetic field at a point midway between the poles will be

Options

A. `2 xx 10^(-5)T`
B. `4 xx 10^(-6) T`
C. `8 xx 10^(-7)T`
D. zero

Answer

C

Explanation

`B= B_(N) + B_(S)= 2 xx (mu_(0))/(4pi).(q_(m))/(r^(2))`
`=2 xx 10^(-7) xx (0.01)/((0.1)/(2))^(2))= 8 xx 10^(-7)T`