A uniform solid sphere of density rho has a cavity of radius R/2. Find the gravitational field at any point in the cavity.

Acc to shell theoram at any point inaide the cavity  gravitational field will be zero because as the force inside the cavity at any point is equal and oppo which leads to zero gravitational field in the cavity. Particles behind any point (execpt centre) increase and distance increases at the same time on opposite side no. Of particles decreases and distance also decreases which leads to equate the forces on both sides