Starting from the centre of the earth having radius $R$,the variation of $g$ (acceleration due to gravity) is shown by:

$A$ narrow but tall cabin is falling freely near the earth's surface. Inside the cabin,two small stones $A$ and $B$ are released from rest (relative to the cabin). Initially $A$ is much above the centre of mass and $B$ is much below the centre of mass of the cabin. $A$ close observation of the motion of $A$ and $B$ will reveal that

Two planets have the same density but different radii. The acceleration due to gravity would be ........

Consider Earth to be a sphere of radius $R_e$ rotating about its own axis with angular speed $\omega$. If $g_{E}$ and $g_{P}$ are the accelerations due to gravity at the equator and the poles respectively,then $(g_{P}-g_{E})$ is given by $\left[\cos (0^{\circ})=\sin (\frac{\pi}{2})=1, \sin (0^{\circ})=\cos (\frac{\pi}{2})=0\right]$

Given below are two statements: One is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A$: If we move from poles to equator,the direction of acceleration due to gravity of earth always points towards the center of earth without any variation in its magnitude.
Reason $R$: At equator,the direction of acceleration due to the gravity is towards the center of earth. In the light of above statements,choose the correct answer from the options given below.

What is the gravitational force on a particle at the centre of the Earth?