# Physics GK 06 - Gravitation

1. Which of the following is true about universal gravitational constant in the case of two bodies each of unit mass having their centres placed at unit distance apart?
[A] It is equal to the force of attraction between them
[B] It is equal to twice the force of attraction between them
[C] It is equal to half the force of attraction between them
[D] It is equal to ten times the force of attraction between them

2. Which of the following laws state that the orbits of the planets are ellipses, with the Sun at one focus of the ellipse?
[A] Kepler’s First law
[B] Kepler’s Second law
[C] Kepler’s Third law
[D] None of the above

3. Kepler’s second law is also known as:
[A] Law of periods
[B] Law of areas
[C] Law of orbits
[D] Law of Planets

4. As per the Kepler’s third law, the square of the time period of revolution of a planet is directly proportional to which of the following?
[A] semi-major axis of its elliptical orbit
[B] cube root of semi-major axis of its elliptical orbit
[C] square of semi-major axis of its elliptical orbit
[D] cube of semi-major axis of its elliptical orbit

5. Which of the following represents the dimensional formula of Universal Gravitational Constant?
[A] M1 L2 T-2
[B] M-1 L1 T-2
[C] M-1 L3 T-2
[D] M1 L3 T-2

6. The Universal Gravitational Constant for two bodies is dependent on which of the following?
[A] Nature of the bodies
[B] Size of the bodies
[C] Nature of medium between the bodies
[D] None of the above

7. Which of the following is incorrect:
[A] Gravitational force of attraction is independent of nature of intervening medium
[B] Gravitational forces are central forces
[C] Gravitational forces are non-conservative forces
[D] All of the above

8. What is the SI unit of acceleration due to gravity?
[A] ms-2
[B] ms-3
[C] Kgms-2
[D] ms-1

9. What is the value of acceleration due to gravity at the centre of the earth?
[A] 1 N/kg
[B] 0
[C] -9.8 N/kg
[D] 9.8 N/kg