What is the depth at which the value of acceleration due to gravity becomes \(\dfrac{1}{{n}}\) times it's value at the surface of the earth? (radius of the earth = \(\mathrm{R}\))  

1.	\(\dfrac R {n^2}\)	2.	\(\dfrac {R~(n-1)} n\)
3.	\(\dfrac {Rn} { (n-1)}\)	4.	\(\dfrac R n\)

The density of a newly discovered planet is twice that of Earth. If the acceleration due to gravity on its surface is the same as that on Earth, and the radius of Earth is \(R,\) what will be the radius of the new planet?

The universal gravitational constant is dimensionally represented as:
1. \(\left[ML^2T^{-1}\right]\)
2. \(\left[M^{-2}L^3T^{-2}\right]\)
3. \(\left[M^{-2}L^2T^{-1}\right]\)
4. \(\left[M^{-1}L^3T^{-2}\right]\)

Rohini satellite is at a height of \(500\) km and Insat-B is at a height of \(3600\) km from the surface of the earth. The relation between their orbital velocity (\(v_R,~v_i\)) is:
1. \(v_R>v_i\)
2. \(v_R<v_i\)
3. \(v_R=v_i\)
4. no specific relation 

For moon, its mass is \(\frac{1}{81}\) of Earth's mass and its diameter is \(\frac{1}{3.7}\) of Earth's diameter. If acceleration due to gravity at Earth's surface is \(9.8~\text{m/s}^2,\) then at the moon, its value is: 

Two spheres of masses \(m\) and \(M\) are situated in air and the gravitational force between them is \(F.\) If the space around the masses is filled with a liquid of specific density \(3,\) the gravitational force will become:
1. \(3F\)
2. \(F\)
3. \(F/3\)
4. \(F/9\)