Magnetic induction due to short magnetic dipole of magnetic moment 4 `Am^(2)` at a point 50 cm from centre of dipole on a line inclined at `30^(@)` with its axis.The magnetic induction is

Options

A. `4.2xx10^(-6)T,41^(@)`
B. `2.2xx10^(-6) T,41^(@)`
C. `4.2xx10^(6)T,21^(@)`
D. `2.2xx10^(-6) T,31^(@)`

Answer

A

Explanation

`B=(mu_(0))/(4pi)(M)/(r^(3))sqrt(3cos^(2)theta+1)`
`=(10^(-7)xx4)/(125xx10^(-3))sqrt(3xx(1)/(4)+1)=4.235xx10^(-6) T`
`phi=tan^(-1)((1)/(2)tantheta)=40^(@)54'41^(@)`