If mass of earth is increased, what will be the effect on gravitational potential,

• A) Decreased
• B) Increased
• C) May be increase or decrease
• D) Remains same

Let F1 be the magnitude of the gravitational force exerted on the Sun by Earth and F2 be the magnitude of the force exerted on Earth by the Sun. Then:

• A) F1 is equal to F2
• B) F1 is much greater than F2
• C) F1 is slightly greater than F2
• D) F1 is slightly less than F2

If the gravitational potential energy of an object is 200 J and its mass is 20 kg, what is its height above the reference point? (Take g = 10 m/s2)

• A) 4 m
• B) 2 m
• C) 10 m
• D) 8 m

At center of the Earth, gravitational force is

• A) Double
• B) Random
• C) Zero
• D) Maximum

The orbital velocity of a satellite at an altitude of 500 km from the surface of earth is,

• A) 11.2 km/s
• B) 7660 m/s
• C) 6400 m/s
• D) 10 Km/s

Earth exerts a gravitational force on the Moon, keeping it in its orbit. The reaction to this force, in the sense of Newton’s third law, is:

• A) the centripetal force on the Moon
• B) the nearly circular orbit of the Moon
• C) the tides due to the Moon
• D) the gravitational force on Earth by the Moon

Which force is considered the weakest among all fundamental forces in nature?

• A) Gravity
• B) Friction force
• C) Electromagnetic force
• D) Weak nuclear force

Let M denote the mass of Earth and let R denote its radius. The ratio g/G at Earth’s surface is:

• A) R^2/M
• B) M/R^2
• C) M/R
• D) MR^2

According to Einstein's theory of general relativity, what is gravity attributed to?

• A) Exchange of virtual particles
• B) Curvature of spacetime
• C) Gravitational waves
• D) Gravitons

Kepler’s First Law says that planets move in

• A) Spiral paths
• B) Elliptical orbits
• C) Random curves
• D) Circular paths

Earth has an orbital period of 365 days and its mean distance from the Sun is 1.495x108 km. The planet Pluto’s mean distance from the Sun is 5.896x109 km. Using Kepler’s third law, Pluto’s orbital period in Earth days will be,

• A) 90000 days
• B) 4500 days
• C) 9000 days
• D) 450 days

Consider the following statements, and then select the correct ones. I. Most of the electrical devices we use require AC voltage. II. Most of the electrical energy sold by power companies is transmitted and distributed as alternating current. III. AC voltage can be easily and efficiently converted from one place to another by means of transformers.

• A) I and II are correct, and III is incorrect.
• B) I, II, and III are correct.
• C) I is correct, and II and III are incorrect.
• D) I and III are correct; II is incorrect.

The approximate value of g at an altitude above Earth equal to one Earth diameter is:

• A) 4.9m/s2
• B) 1.1m/s2
• C) 2.5m/s2
• D) 1.9m/s2

If the gravitational potential at a certain height is zero, what can you conclude about the gravitational potential energy at that height?

• A) It cannot be determined
• B) It is infinite
• C) It is positive
• D) It is also zero

What is the dimension of the universal gravitational constant G?

• A) M-1L2T-2
• B) M-1L3T-2
• C) M-1L3T-1
• D) M-2L3T-2

Consider two planets, Planet A and Planet B. Planet A has an average distance from the Sun (rA) that is four times that of Planet B (rB). If the orbital period of Planet B is 3 years, what would be the expected orbital period of Planet A? (Hint: use Kepler’s law)

• A) 9 years
• B) 3 years
• C) 6 years
• D) 12 years

If radius of earth is increased by two time, the volume of earth increased by

• A) 8 times
• B) 27 times
• C) 4 times
• D) 9 times

Suitable units for the gravitational constant G are:

• A) m3/ (kg•s2)
• B) m/s2
• C) kg•m/s2
• D) N•s/m

A rod with moment of inertia of 5 Kgm2 and oscillates with a period of 3.14 seconds, its torsion constant “k” is,

• A) 20 Nm
• B) 10 Nm
• C) 15 Nm
• D) 0.62 Nm

The gravitational constant G has the derived units:

• A) N•m2/kg2
• B) N•m/kg
• C) N•kg/m
• D) N•m