Two identical short bar magnets, each having magnetic moment of `10Am^(2)`, are arranged such that their axial lines are perpendicular to each other and their centres be along the same straigh line in a horizonetal plane. If the distance between their centres is `0.2m`, the resultant magnetic induction at a point midway between them is
`(mu_(0)=4pixx10^(-7)Hm^(-1))`

Options

A. `sqrt(2)xx10^(-7)` Tesla
B. `sqrt(5)xx10^(-7)` Tesla
C. `sqrt(2)xx10^(-3)` Tesla
D. `sqrt(5)xx10^(-3)` Tesla

Answer

D

Explanation

From figure `B_(net)=sqrt(B_(a)^(2)+B_(e)^(2))`
`sqrt((mu_(0)/(4pi).(2M)/d^(3))^(2)+(mu_(0)/(4pi).M/d^(3))^(2))`
`=sqrt(5).mu_(0)/(4pi).M/d^(3)=sqrt(5)xx10^(-7)xx10/(0.1)^(3)=sqrt(5)xx10^(-3)` Tesla