Two short magnet having magnetic moment in the ratio `27:8`, when placed on the opposite sides of a deflection magnetometer, produce no deflection. If the distance of the weaker magnet is `0.12m` from the centre of deflection magnetometer, the distance of the stronger magnet from the centre is

Explanation

`B = (mu_(0))/(4pi) (2M)/(d^(3))`
`therefore (mu_(0))/(4pi) (2M_(1))/(d_(1)^(3)) = (mu_(0))/(4pi) (2M_(2))/(d_(2)^(3))`
`(M_(1))/(M_(2)) = (d_(1)^(3))/(d_(2)^(3))`
`therefore (d_(1))/(d_(2)) = ((M_(1))/(M_(2)))^(1//3) = ((27)/(8))^(1//3) = (3)/(2)`
`rArr d_(1) = d_(2) (3)/(2) = 0.12xx 15 = 0.18 m`