Question

Two short magnets having magnetic moments in the ratio `27:8`, when placed on opposite sides of a deflection magnetometer produce no deflection. If the distance of weaker magnet is `0*12m` from the centre of deflection magnometer, what is the distance of stronger magnet from the centre?

Answer 1

Here, `M_1/M_2=27/8`,
`r_2=0*12m=12cm, r_1=?`
In the null method, `M_1/M_2=(r_1/r_2)^3=27/8`
`r_1/r_2=3/2, r_1=3/2r_2=3/2xx12=18cm`