If two bar magnets of different magnetic lengths have equal moments, then the pole strength is :
If the north pole of one bar magnet is moved closer to the south pole of another bar magnet, then the two poles will ___________.
Two short magnets with pole strengths of 900Am and 100Am are placed with their axes in the same vertical line, with similar poles facing each other. Each magnet has a length of 1cm. When separation between the nearer poles is 1cm, the weight of the upper magnet is supported by the repulsive force between the magnets. If g=10ms−2, then the mass of upper magnet is (x×10−4)