Two unlike magnetic poles of unequal strengths are 10 cm apart in air. They attract each other with a force of 64 dynes. Calculate the pole strengths of the poles if one pole is 4 times stronger than the other.

Two poles one of which is 5 times are strong as the other are 25 cm apart in air. They repel each other with a force of 500 dynes. Find the strength of each pole.

If two equal and similar charges 0.03 m apart in air, repel each other with a force of 4.5 kg-f, then determine the charge in coulomb.

Two identical thin bar magnets each of pole strength 'm' and magnetic length are placed at 90^@ to each other with north pole of one magnet touching the south pole of the other magnet. The magnetic moment of the system is