1. What causes tides in the sea?
a) Earth’s atmospheric effects
b) Gravitational pull of Venus
c) Gravitational pull of the Sun
d) Gravitational pull of the Moon
Answer: d
2. Why do astronauts experience weightlessness in a spacecraft orbiting Earth?
a) Due to inertia
b) Due to acceleration
c) Due to zero gravity
d) Due to orbital motion
Answer: c
3. A person inside a satellite feels weightless because:
a) Gravitational force is zero
b) Moon’s gravity balances Earth’s gravity
c) Gravitational pull equals centripetal force
d) Satellite design cancels gravitational effect
Answer: a
4. What causes the sensation of weightlessness in a spacecraft?
a) Absence of external gravity
b) Orbital acceleration equals gravitational acceleration
c) Gravity is present outside but not inside
d) No energy in the spacecraft
Answer: b
5. What happens to ‘g’ (acceleration due to gravity) as one moves from the equator to the poles?
a) Remains unchanged
b) Decreases
c) Increases
d) No effect
Answer: c
6. What is the gravitational constant ‘G’?
a) Gravitational constant
b) Gravitational attraction
c) Gravitational force
d) Acceleration due to gravity
Answer: a
7. The law of gravitation is applicable to:
a) Earth and Moon
b) Planets and the Sun
c) Earth and its objects
d) Any two masses
Answer: d
8. The intensity of Earth’s gravitational field is maximum at:
a) The poles
b) The equator
c) The Earth’s center
d) The surface
Answer: a
9. What is true about the Moon’s gravity?
a) It is 1/6th of Earth’s gravity
b) It is 1/6th of Mars’ gravity
c) It is 1/8th of Earth’s gravity
d) It is 1/8th of Mars’ gravity
Answer: a
10. If the orbit of a planet is elliptical, the point where the Sun is located is called:
a) Center
b) Circumcenter
c) Incenter
d) Focus
Answer: d
11. Why does Earth retain its atmosphere?
a) Winds
b) Clouds
c) Gravity
d) Earth’s rotation
Answer: c
12. The Moon’s gravity is:
a) 1/6th of Earth’s gravity
b) 1/8th of Earth’s gravity
c) Equal to Earth’s gravity
d) Negligible
Answer: a
Gravitational Effects & Forces
13. The acceleration due to gravity at a distance of 2R from the surface of Earth (R = Earth’s radius) is:
a) g/3
b) g/4
c) g/9
d) g/2
Answer: c
14. If the distance between two bodies is doubled, the gravitational force between them becomes:
a) 2F
b) ½ F
c) 4F
d) ¼ F
Answer: d
15. What is the minimum escape velocity required for a rocket to leave Earth?
a) 5 km/s
b) 6 km/s
c) 11 km/s
d) 15 km/s
Answer: c
16. What is the dimension of the universal gravitational constant (G)?
a) M⁻¹L³T⁻²
b) M⁻¹L³T²
c) ML²T⁻²
d) M⁻²
Answer: a
17. What is the mass of a body on the Moon if it is 100 kg on Earth (gₑ = 10 m/s², gₘ = gₑ/6)?
a) 100/6 kg
b) 60 kg
c) 100 kg
d) 600 kg
Answer: c
18. A pendulum taken to the Moon will have its time period:
a) Unchanged
b) Decreased
c) Zero
d) Increased
Answer: d
19. When standing in a lift accelerating downward, a person’s apparent weight is:
a) Greater than actual weight
b) Twice the actual weight
c) Less than actual weight
d) Equal to actual weight
Answer: c
20. Carrying two water buckets in each hand feels easier than carrying one in one hand because:
a) The weights are balanced
b) The center of gravity stays inside the body
c) The center of gravity and equilibrium fall within the feet
d) Resultant weight is zero
Answer: c
Orbital Motion & Satellites
21. A satellite having the same period of rotation as Earth’s is called:
a) Polar satellite
b) Stationary satellite
c) Geostationary satellite
d) INSAT
Answer: c
22. What is the ratio of velocities when two stones are thrown (one upward, one downward) with equal speed from a cliff and hit the ground?
a) 1:1
b) 1:2
c) 1:4
d) Cannot be determined
Answer: a