Two north poles of pole strengths 4 A−m and 16 A−m are separated by a distance of 20 cm. The position of the neutral point from 4 A−m pole is :
The force between two similar poles of strengths 10 Am and 40 Am separated by a distance of 20 cm is
Two magnetic poles of pole strengths 324 mA−m and 400 mA−m. are kept at a distance of 10 cm in air. The null point will be at a distance of ––––––––– ( in cm ), on the line joining the two poles, from the weak pole if they are like poles :