The mass density of a solid sphere is $\rho$. The radius of the sphere is $R$. The gravitational field at a distance $r$ from the centre of the sphere inside it is:

$3$ particles each of mass $m$ are kept at the vertices of an equilateral triangle of side $L$. The gravitational field at the centre due to these particles is

$A$ uniform sphere has radius $R$ and mass $M$. The magnitude of the gravitational field at distances $r_1$ and $r_2$ from the centre of the sphere are $E_1$ and $E_2$ respectively. The ratio $E_1: E_2$ is ($r_1 > R$ and $r_2 < R$).

Which one of the following graphs correctly represents the variation of the gravitational field $(I)$ with the distance $(r)$ from the centre of a spherical shell of mass $M$ and radius $a$?

$A$ spherical shell is cut into two pieces along a chord as shown in the figure. $P$ is a point on the plane of the chord. The magnitude of the gravitational field at $P$ due to the upper part is $I_1$ and that due to the lower part is $I_2$. What is the relation between them?

What is the intensity of the gravitational field at the center of a spherical shell?