Question

With the help of strong magnets made from magnico, one may perform the following experiment. Similar magnets A and B are placed on a line with like poles next to each other. Then magnet B is placed on one edge and kept in equilibrium in an inclined position (Fig.) by the force of interaction of the poles NN. Determine the force of interaction and the strength of the magnetic poles if magnet B of length 10 cm and weight 100 g-wt is in equilibrium at an angle α of 10°. The poles may be considered to be point poles located at the ends of the magnets. Is the equilibrium of magnet B stable?

 

Answer 1

Answer: F ≅ 49 g-wt, m ≅ 384 e.m.u. The equilibrium is stable.

Explanation: 

Acting on magnet B are the moment due to the weight \Pl cos a and the moment due to the magnetic interaction