Q.1 The value of the universal gravitational constant (G) is:
6.67 × 10^-11 N·m²/kg²
9.81 m/s²
1.6 × 10^-19 C
3 × 10^8 m/s
Explanation - The universal gravitational constant G has a fixed value of 6.67 × 10^-11 N·m²/kg², which appears in Newton's law of gravitation.
Correct answer is: 6.67 × 10^-11 N·m²/kg²
Q.2 According to Newton's law of gravitation, the gravitational force between two masses depends on:
Only the distance between them
Only their masses
Their masses and the distance between them
Their volumes
Explanation - Newton's law states that the gravitational force is directly proportional to the product of their masses and inversely proportional to the square of the distance between them.
Correct answer is: Their masses and the distance between them
Q.3 The gravitational force between two objects is halved when:
Distance between them is doubled
Distance between them is halved
One mass is doubled
One mass is halved
Explanation - Gravitational force is inversely proportional to the square of distance. Doubling the distance decreases the force to 1/4, which is a reduction by half when compared to initial.
Correct answer is: Distance between them is doubled
Q.4 Acceleration due to gravity (g) on Earth's surface is approximately:
8.9 m/s²
9.8 m/s²
10.8 m/s²
7.8 m/s²
Explanation - The standard value of acceleration due to gravity on Earth's surface is 9.8 m/s².
Correct answer is: 9.8 m/s²
Q.5 If Earth's radius decreases but mass remains the same, the value of g will:
Increase
Decrease
Remain the same
Become zero
Explanation - Since g = GM/R², decreasing R increases g when M remains constant.
Correct answer is: Increase
Q.6 Which planet has the highest surface gravity?
Earth
Mars
Jupiter
Venus
Explanation - Jupiter is the largest planet and has the highest surface gravity among planets in our solar system.
Correct answer is: Jupiter
Q.7 The weight of an object is:
Constant everywhere
Directly proportional to g
Independent of gravity
Same as mass
Explanation - Weight = Mass × g, so it changes with varying gravitational acceleration.
Correct answer is: Directly proportional to g
Q.8 Escape velocity on Earth is approximately:
7.8 km/s
9.8 km/s
11.2 km/s
15.0 km/s
Explanation - The escape velocity is the minimum speed required for an object to escape Earth's gravitational pull, approximately 11.2 km/s.
Correct answer is: 11.2 km/s
Q.9 Gravitational force is considered a:
Contact force
Non-contact force
Electrostatic force
Frictional force
Explanation - Gravitational force acts at a distance without physical contact between bodies.
Correct answer is: Non-contact force
Q.10 The value of g decreases with:
Increase in altitude
Decrease in altitude
Decrease in distance from Earth's center
Increase in Earth's mass
Explanation - As altitude increases, distance from Earth's center increases, reducing g because g is inversely proportional to distance squared.
Correct answer is: Increase in altitude
Q.11 The force that keeps the planets in orbit around the Sun is:
Electromagnetic force
Gravitational force
Centrifugal force
Nuclear force
Explanation - The Sun's gravitational pull keeps planets in their elliptical orbits.
Correct answer is: Gravitational force
Q.12 The value of g at Earth's center is:
Maximum
Zero
Equal to surface value
Half the surface value
Explanation - At Earth's center, gravitational forces from all directions cancel out, resulting in zero net force.
Correct answer is: Zero
Q.13 Gravitational potential energy is negative because:
It represents work done by the system
It represents attractive forces
It represents repulsive forces
It is zero at Earth's surface
Explanation - Gravitational potential energy is negative since the force is attractive and work must be done to separate the masses.
Correct answer is: It represents attractive forces
Q.14 Which of these quantities is scalar?
Gravitational field intensity
Acceleration due to gravity
Gravitational potential
Weight
Explanation - Gravitational potential is a scalar quantity as it has only magnitude and no direction.
Correct answer is: Gravitational potential
Q.15 Two bodies attract each other with a force F. If the distance between them is doubled, the new force is:
F/2
F/3
F/4
F/8
Explanation - According to Newton's law of gravitation, force is inversely proportional to the square of the distance. Doubling the distance decreases the force by 4 times.
Correct answer is: F/4
Q.16 Which factor affects the value of g on Earth's surface?
Mass of the object
Shape of the object
Altitude and latitude
Temperature
Explanation - Altitude and latitude affect g due to Earth's shape and rotation.
Correct answer is: Altitude and latitude
Q.17 Geostationary satellites revolve around the Earth in:
12 hours
24 hours
48 hours
6 hours
Explanation - A geostationary satellite matches Earth's rotation and takes 24 hours to complete one orbit.
Correct answer is: 24 hours
Q.18 The unit of gravitational potential is:
Joule
Joule/kg
Newton
m/s²
Explanation - Gravitational potential is energy per unit mass, so its unit is Joule per kilogram.
Correct answer is: Joule/kg
Q.19 The orbital speed of a satellite depends on:
Mass of the satellite
Altitude of the orbit
Shape of the satellite
Weight of the satellite
Explanation - Orbital speed depends on the altitude as it determines the distance from Earth's center.
Correct answer is: Altitude of the orbit
Q.20 Which of the following is correct about weightlessness?
Gravity is zero
Mass becomes zero
Apparent weight becomes zero
Actual weight increases
Explanation - Weightlessness occurs when apparent weight becomes zero, such as in free-fall conditions.
Correct answer is: Apparent weight becomes zero
Q.21 The gravitational field at a point is defined as:
Force experienced by a unit charge
Force experienced by a unit mass
Potential energy per unit mass
Work done per unit mass
Explanation - Gravitational field is the force per unit mass experienced at a point due to a mass.
Correct answer is: Force experienced by a unit mass
Q.22 The orbital period of a satellite increases when:
Altitude increases
Altitude decreases
Earth's mass decreases
Gravitational constant increases
Explanation - Higher altitude means greater distance from Earth's center, resulting in a longer orbital period.
Correct answer is: Altitude increases
Q.23 Which of the following quantities remains constant for a satellite in circular orbit?
Velocity
Speed
Acceleration
Angular velocity
Explanation - A satellite in a circular orbit maintains constant angular velocity.
Correct answer is: Angular velocity
Q.24 If the mass of Earth doubles and its radius halves, the value of g will:
Remain the same
Double
Increase by 8 times
Decrease by 4 times
Explanation - g = GM/R², so doubling M and halving R increases g by a factor of 8.
Correct answer is: Increase by 8 times