The dependence of acceleration due to gravity $g$ on the distance $r$ from the centre of the earth, assumed to be a sphere of radius $R$ of uniform density, is as shown in which of the following figures?

If the mass and radius of a planet are double those of the Earth,what will be the acceleration due to gravity on this planet compared to the acceleration due to gravity on Earth?

Two satellites $P$ and $Q$ are moving in different circular orbits around the Earth (radius $R$). The heights of $P$ and $Q$ from the Earth's surface are $h_p$ and $h_Q$,respectively,where $h_p = R / 3$. The accelerations of $P$ and $Q$ due to Earth's gravity are $g_p$ and $g_Q$,respectively. If $g_p / g_Q = 36 / 25$,what is the value of $h_Q$?

Assuming the density of the Earth is constant, which graph correctly represents the variation of acceleration due to gravity $(g)$ with the distance $(r)$ from the center of the Earth (radius of the Earth $= R$)?

The average density of the Earth is [ $g$ is acceleration due to gravity]:

$A$ newly discovered planet has a density eight times the density of the earth and a radius twice the radius of the earth. The time taken by a $2\, kg$ mass to fall freely through a distance $S$ near the surface of the earth is $1$ second. Then the time taken for a $4\, kg$ mass to fall freely through the same distance $S$ near the surface of the new planet is ....... $\sec$.