Mass is at a distance '2a' from the centre of a ring of radius 'a' along the axis of the ring . Point P is situated midway between the centre of the ring and
on the axis of the ring. What should be the mass(M) of the ring such that the gravitational field at point P is zero:
Field due to point mass mo at P
Field due to ring at point p
If the net field at point p is zero these two fields should be equal.