A magnetic dipole is under the influence of two orthogonal magnetic fields, `B_(1) = 0.5 xx 10^(-3) T and B_(2) = 0.866 xx 10^(-3)T`. If the dipole comes to stable equilibrium at an angle `theta` with respect to `B_(2)` field, then the value of `theta` is

Options

A. `45^(@)`
B. `30^(@)`
C. `60^(@)`
D. `90^(@)`

Answer

B

Explanation

From tangent law, we have,
`mB_(2) sin theta = mB_(1) sin (90^(@) - theta)`

`rArr tan theta = (B_(1))/(B_(2)) = (0.5 xx 10^(-3))/(0.866 xx 10^(-3))`
`= ((1)/(2))/((sqrt3)/(2)) = (1)/(sqrt3)`
`tan theta = tan 30^(@)`
`rArr theta = 30^(@)`