Two magnets $A$ and $B$ are identical and these are arranged as shown in the figure. Their length is negligible in comparison to the separation between them. A magnetic needle is placed between the magnets at point $P$ which gets deflected through an angle $\theta$ under the influence of magnets. The ratio of distance $d_1$ and $d_2$ will be 

Two short magnets of equal dipole moments $M$, are fastened perpendicularly at their centre (figure). The magnitude of the magnetic field, at a distance $d$ from the centre, on the bisector of the right angle, is 

Which graph may best represent the current vs deflection curve in a tangent galvanometer?

A magnetic needle lying parallel to a magnetic field requires $W$ unit(s) of work to turn it through $60°$. The torque needed to maintain the needle in this position will be,