 # Gravitation MCQs for NEET

Gravitation is one of the fundamental forces of attraction that exists between the objects. The term gravity is used for gravitation, but gravitation is defined as the theory that explains the attraction while gravity is defined as the force that pulls objects towards each other. Newton is the unit of gravitation force.

The gravitational force between the two objects is directly proportional to the product of their masses and is inversely proportional to the square of the distance between their centres.

1. What happens to the gravitational potential at the centre of the uniform spherical shell which shrinks gradually?

(a) Remains constant

(b) Decreases

(c) Increases

(d) Oscillates

2. What is the relation between the escape velocity and orbital velocity of a satellite, if the satellite is close to the earth’s surface?

(a) $v_{e}=\sqrt{2v_{0}}$

(b) $v_{e}=\sqrt2v_{0}$

(c) $v_{0}=\sqrt{2v_{e}}$

(d) v0 = ve

Answer: (b) $v_{e}=\sqrt2v_{0}$

3. What happens to the weight of the body if the weight becomes $\frac{1}{16}$ at a certain. Also, consider the radius of the earth to be R.

(a) 4R

(b) 15R

(c) 5R

(d) 3R

4. What is the maximum height attained by the rocket above the surface of the earth if the mass of the rocket is M, and the initial speed to be V. Assume that R is the radius of the earth.

(a) $\frac{R}{\frac{gR}{2V^{2}}-1}$

(b)$\frac{R}{\frac{2gR}{V^{2}}-1}$

(c) $R({\frac{gR}{2V^{2}}-1})$

(d) $R({\frac{2gR}{V^{2}}-1})$

Answer: (b) $\frac{R}{\frac{2gR}{V^{2}}-1}$

5. What is the increase in the potential energy of the body with mass m if the body is taken at the height h which is equal to the radius of the earth?

(a) mgR

(b) 2mgR

(c) $\frac{1}{2}mgR$

(d) $\frac{1}{4}mgR$

Answer: (c) $\frac{1}{2}mgR$

6. Consider a body of mass m which needs to be moved from an orbit of radius 2R to 3R. What is the energy required

(a) $\frac{GMm}{12R^{2}}$

(b) $\frac{GMm}{6R}$

(c) $\frac{GMm}{8R}$

(d) $\frac{GMm}{3R^{2}}$

Answer: (b) $\frac{GMm}{6R}$

7. The distance between the closest planet and the sun is r1 while the distance between the farthest planet and the sun is r2. The linear velocities of these planets is v1 and v2 respectively. What is the ratio of $\frac{v_{1}}{v_{2}}$

(a) $(\frac{r_{1}}{r_{2}})^{2}$

(b) $(\frac{r_{1}}{r_{2}})$

(c) $(\frac{r_{2}}{r_{1}})$

(d) $(\frac{r_{2}}{r_{1}})^{2}$

Answer: (c) $(\frac{r_{2}}{r_{1}})$

8. Choose the factor on which the orbital velocity does not depend when the satellite is orbiting close to the earth’s surface

(a) The mass of the earth

(b) The mass of the satellite

(d) The radius of the earth

Answer: (b) The mass of the satellite

9. If a satellite takes time T for revolution, the the kinetic energy is proportional to

(a) $\frac{1}{T}$

(b) $T^{\frac{-2}{3}}$

(c) $\frac{1}{T^{2}}$

(d)$\frac{1}{T^{3}}$

Answer: (b) $T^{\frac{-2}{3}}$

10. The atmosphere around the earth is held by

(a) Gravity

(b) Winds

(c) Clouds

(d) None of the above