Question

whay does the value of gravitational acceleration decreases as we go inside the Earth​

Answer 1

As the depth increased the mass of the earth decreases. At the surface of earth this value will be maximum because radius will be maximum. When radius becomes less this value also decreases. Hence acceleration due to gravity decreases with increase in the depth.

Answer 2

Since force due to gravity is proportional to the product of the masses, less force is exerted on you and hence, the value of g decreases. ... Inside a solid, uniform sphere, the total gravity at a point a distance r from the centre is equal to the gravity of the smaller sphere whose radius is r.