Suppose we want to verify the analogy between electrostatic and magnetostatic by an explicit experiment. Consider the motion of (i) electric dipole p in an electrostatic field E and (ii) magnetic dipole M in a magnetic field B. Write down a set of conditions on E, B, pM so that the two motions are verified to be identical. (Assume identical initial conditions).

Hint: The torque in both conditions should be the same.
Step 1: Now, suppose that the angle between M and B is θ.
Torque on magnetic dipole moment M in magnetic field B,

     τ= MBsinθ
Step 2: Two motions will be identical, if;
     pEsinθ = MBsin θ
        pE = MB                            ..(i)
But,        E = cB,
Step 3:
 putting this value in Eq. (i);
  pcB = MB
  p = Mc