By which curve will the variation of gravi

For hollow sphere
${V_{in}} = \frac{{ - GM}}{R}$, ${V_{{\rm{surface}}}} = \frac{{ - GM}}{R},\,\,{V_{out}} = \frac{{ - GM}}{r}$
i.e. potential remain constant inside the sphere and it is equal to potential at the surface and increase when the point moves away from the surface of sphere.