Grade 9
Conceptual Questions
Who proposed the universal law of gravitation?
a) Albert Einstein
b) Isaac Newton
c) Galileo Galilei
d) Nikola Tesla
Answer: b
The gravitational force between two objects is:
a) Repulsive
b) Attractive
c) Depends on the distance
d) Zero
Answer: b
Gravitational force depends on:
a) Mass of the objects
b) Distance between the objects
c) Both a and b
d) None of the above
Answer: c
Which of these statements is true about the gravitational force?
a) It acts only on heavy objects.
b) It acts in the absence of air.
c) It acts between any two masses.
d) It acts only at large distances.
Answer: c
The SI unit of gravitational constant (G) is:
a) N m²/kg²
b) m/s²
c) N
d) kg/m³
Answer: a
Formula-Based Questions
The formula for gravitational force is:
a)
F=G
2
b)
F=G
c)
G
r
F=G
d)
F=G
r
2
Answer: b
The value of the universal gravitational constant (G) is approximately:
a)
6.67
11
N m²/kg²
6.67×10
−11
N m²/kg²
b)
9.8
m/s²
9.8m/s²
c)
6.67
11
kg m/s²
6.67×10
−11
kg m/s²
d)
9.8
kg m²/s²
9.8kg m²/s²
Answer: a
The weight of an object on the Moon is approximately:
a)
of its weight on Earth
b)
6
6
of its weight on Earth
c) Equal to its weight on Earth
d)
10
10
of its weight on Earth
Answer: b
If the distance between two objects is doubled, the gravitational force
becomes:
a) Twice as strong
b) Four times stronger
c) Half as strong
d) One-fourth as strong
Answer: d
What is the relation between gravitational force and the distance between
two masses?
a) Directly proportional
b) Inversely proportional
c) Inversely proportional to the square of the distance
d) No relation
Answer: c
Application-Based Questions
The weight of a 10 kg object on Earth is:
a) 10 N
b) 98 N
c) 9.8 N
d) 100 N
Answer: b
A body weighs 60 N on the surface of the Earth. Its mass is:
a) 60 kg
b) 6 kg
c) 10 kg
d) 600 kg
Answer: c
The value of acceleration due to gravity (g) on the surface of the Earth is
approximately:
a)
6.67
m/s²
6.67m/s²
b)
9.8
m/s²
9.8m/s²
c)
11.2
m/s²
11.2m/s²
d)
15
m/s²
15m/s²
Answer: b
Which of these is NOT affected by gravity?
a) The Moon
b) Light
c) Earth’s atmosphere
d) Mass
Answer: d
What happens to the gravitational force between two objects if their
masses are doubled?
a) It becomes four times stronger.
b) It becomes half as strong.
c) It remains the same.
d) It doubles.
Answer: a
Higher-Order Thinking Questions
Why is there no atmosphere on the Moon?
a) It is too far from Earth.
b) It has no magnetic field.
c) It has low gravitational force.
d) It rotates too slowly.
Answer: c
Satellites remain in orbit because:
a) Gravitational force and centripetal force balance.
b) Gravity pulls them towards Earth.
c) They are stationary.
d) There is no gravity in space.
Answer: a
If the radius of Earth decreases but its mass remains the same, the value
of g:
a) Increases
b) Decreases
c) Remains the same
d) Becomes zero
Answer: a
What happens to an object’s weight as it moves higher above the Earth’s
surface?
a) Increases
b) Decreases
c) Remains the same
d) Becomes zero
Answer: b
Why does an astronaut feel weightless in space?
a) No gravity acts in space.
b) Gravitational force and centripetal force cancel each other.
c) They are too far from Earth.
d) The mass of the astronaut decreases.
Answer: b
Conceptual Questions
If the mass of one object is tripled and the distance between two objects
is halved, the gravitational force will:
a) Remain the same
b) Increase by 6 times
c) Increase by 12 times
d) Increase by 24 times
Answer: d
The value of acceleration due to gravity (g) is maximum at:
a) The poles
b) The equator
c) The center of Earth
d) The Moon’s surface
Answer: a
Which of the following does NOT affect the value of acceleration due to
gravity (g)?
a) Mass of the Earth
b) Radius of the Earth
c) Altitude
d) Mass of the object
Answer: d
The Earth’s gravitational force on an object is called its:
a) Mass
b) Weight
c) Acceleration
d) Density
Answer: b
The force of gravitation between two objects does not depend on:
a) Masses of the objects
b) Distance between the objects
c) Shape of the objects
d) Gravitational constant (G)
Answer: c
Numerical Questions
A 5 kg object is placed on Earth. What is its weight?
a) 5 N
b) 9.8 N
c) 49 N
d) 98 N
Answer: c
A 100 N force acts between two objects. If the distance between them is
doubled, what will be the new force?
a) 100 N
b) 50 N
c) 25 N
d) 200 N
Answer: c
If the gravitational force between two objects is 16 N and the distance
between them is halved, the new force will be:
a) 8 N
b) 32 N
c) 64 N
d) 4 N
Answer: c
An object of mass 10 kg is taken to a planet where g =
12
m/s
12m/s
. What is its weight on that planet?
a) 120 N
b) 98 N
c) 60 N
d) 100 N
Answer: a
The Moon’s mass is approximately
81
1/81 of the Earth’s mass, and its radius is
4
1/4 of Earth’s radius. What is the approximate value of g on the Moon
compared to Earth?
a)
16
1/16
b)
81
1/81
c)
1/6
d)
1/2
Answer: c
Application-Based Questions
A geostationary satellite orbits Earth because of:
a) Gravitational force
b) Centripetal force
c) Both a and b
d) None of the above
Answer: c
The escape velocity on Earth is approximately:
a)
11.2
km/s
11.2km/s
b)
9.8
km/s
9.8km/s
c)
8.6
km/s
8.6km/s
d)
12.5
km/s
12.5km/s
Answer: a
An apple falls from a tree due to:
a) Magnetic force
b) Electric force
c) Gravitational force
d) Atmospheric pressure
Answer: c
Why does the value of g vary with altitude?
a) Distance from the Earth’s center changes.
b) Mass of the object changes.
c) Radius of Earth increases.
d) Gravitational constant changes.
Answer: a
Artificial satellites are used for:
a) Communication
b) Weather forecasting
c) Scientific research
d) All of the above
Answer: d
Higher-Order Thinking Questions
If Earth shrinks but its mass remains constant, how would g change?
a) Decrease
b) Increase
c) Remain the same
d) Become zero
Answer: b
The weight of a person in a lift moving upward with acceleration increases
because:
a) Gravitational force decreases
b) Normal force increases
c) Gravitational force increases
d) Weight depends on speed, not acceleration
Answer: b
An object is thrown upwards. What happens to its weight as it rises?
a) Increases
b) Decreases
c) Remains constant
d) Becomes zero
Answer: c
If the mass of Earth is doubled and its radius remains the same, the value
of g would:
a) Remain unchanged
b) Double
c) Halve
d) Quadruple
Answer: b
What would happen if there were no gravitational force on Earth?
a) All objects would fly off.
b) The Moon would drift away.
c) The atmosphere would disappear.
d) All of the above
Answer: d
