$A$ uniform sphere of mass $M$ and radius $R$ is surrounded by a concentric spherical shell of the same mass but radius $2R$. $A$ point mass $m$ is kept at a distance $x$ $(R < x < 2R)$ in the region bounded by the spheres as shown in the figure. The net gravitational force on the particle is:

Statement $(I)$: The force of attraction due to a hollow spherical shell of uniform density on a point mass situated inside it is always zero.
Statement $(II)$: The force of attraction between a hollow spherical shell of uniform density and a point mass situated outside is the same as if the entire mass of the shell were concentrated at the center of the shell.
Which of the following is correct?

According to Newton's law of gravitation,every object in the universe exerts a gravitational force on every other object. Why do two objects not move towards each other?

The change in the value of acceleration of the earth towards the sun,when the moon moves from the position of a solar eclipse to the position on the other side of the earth in line with the sun,is: (mass of the moon $= 7.36 \times 10^{22} \ kg$,radius of the moon's orbit $= 3.8 \times 10^8 \ m$).

The mass of the moon is $1\%$ of the mass of the earth. The ratio of the gravitational pull of the earth on the moon and that of the moon on the earth will be

What is the strength of the gravitational force compared to the strong nuclear force?