30 MCQ Questions for Class 9 Science: Chapter 9 Gravitation
Question 1. The universal law of gravitation states that every object in the universe attracts every other object with a force which is:
a) Directly proportional to the square of the distance between them
b) Inversely proportional to the product of their masses
c) Inversely proportional to the square of the distance between them
d) Directly proportional to the product of their masses
Answer:
c) Inversely proportional to the square of the distance between them
Question 2. What is the value of the universal gravitational constant (G)?
a) 6.673 × 10⁻¹¹ N m²/kg²
b) 9.8 m/s²
c) 6.674 × 10⁻¹⁰ N m²/kg²
d) 5.972 × 10²⁴ kg
Answer:
a) 6.673 × 10⁻¹¹ N m²/kg²
Question 3. The acceleration due to gravity ‘g’ is:
a) Same everywhere on the Earth
b) Different at different places on Earth
c) Dependent on the mass of the object
d) Always 9.8 m/s²
Answer:
b) Different at different places on Earth
Question 4. What is the weight of an object on the Moon compared to its weight on the Earth?
a) The same
b) Six times less
c) Six times more
d) Depends on the object’s mass
Answer:
b) Six times less
Question 5. If the distance between two objects is doubled, the gravitational force between them will:
a) Double
b) Become four times
c) Become half
d) Become one-fourth
Answer:
d) Become one-fourth
Question 6. The mass of an object is 60 kg on the Earth. What is its mass on the Moon?
a) 60 kg
b) 10 kg
c) 6 kg
d) 100 kg
Answer:
a) 60 kg
Question 7. What is the effect of altitude on the acceleration due to gravity?
a) It increases with altitude
b) It decreases with altitude
c) It remains constant
d) It first decreases then increases
Answer:
b) It decreases with altitude
Question 8. A satellite orbiting the Earth feels a gravitational force. This force is due to:
a) The Moon
b) The Sun
c) The Earth
d) The atmosphere
Answer:
c) The Earth
Question 9. The pressure exerted by an object on a surface is:
a) Directly proportional to area
b) Inversely proportional to area
c) Independent of the area
d) Dependent on the material of the object
Answer:
b) Inversely proportional to area
Question 10. If an object is partially immersed in a fluid, it experiences an upward force. This principle is known as:
a) Pascal’s Principle
b) Archimedes’ Principle
c) Newton’s Law of Gravitation
d) Boyle’s Law
Answer:
b) Archimedes’ Principle
Question 11. The buoyant force on an object immersed in a liquid depends on:
a) The mass of the object
b) The volume of the object
c) The density of the liquid
d) Both b and c
Answer:
d) Both b and c
Question 12. Archimedes’ Principle is used in designing:
a) Airplanes
b) Cars
c) Ships
d) Rockets
Answer:
c) Ships
Question 13. What causes buoyancy?
a) Density of an object greater than the fluid
b) Density of an object less than the fluid
c) Upward force exerted by the fluid
d) Gravitational pull of the earth
Answer:
c) Upward force exerted by the fluid
Question 14. Which of the following will float in water?
a) A substance with density greater than 1 g/cm³
b) A substance with density equal to 1 g/cm³
c) A substance with density less than 1 g/cm³
d) A substance with density much greater than 1 g/cm³
Answer:
c) A substance with density less than 1 g/cm³
Question 15. Why do objects weigh less in water?
a) Due to the surface tension of water
b) Due to the buoyant force of water
c) Due to the decrease in mass of the object
d) Due to the viscosity of water
Answer:
b) Due to the buoyant force of water
Question 16. The pressure exerted by a fluid at any point inside it is:
a) Same in all directions
b) Different in different directions
c) Only in the upward direction
d) Only in the downward direction
Answer:
a) Same in all directions
Question 17. The thrust on a surface is equal to:
a) Mass x Acceleration
b) Weight x Area
c) Weight / Area
d) Mass / Volume
Answer:
c) Weight / Area
Question 18. The SI unit of pressure is:
a) Pascal
b) Newton
c) Joule
d) Watt
Answer:
a) Pascal
Question 19. The weight of an object on the moon is:
a) Same as on Earth
b) Less than on Earth
c) More than on Earth
d) Zero
Answer:
b) Less than on Earth
Question 20. An object immersed in a fluid experiences an upward force. This principle is known as:
a) Pascal’s Law
b) Newton’s Law
c) Archimedes’ Principle
d) Bernoulli’s Principle
Answer:
c) Archimedes’ Principle
Question 21. The value of acceleration due to gravity (g) on the surface of the Earth is approximately __________ m/s².
Fill in the blank.
Answer:
9.8
Question 22. Objects with mass greater than the fluid in which they are immersed will __________.
Fill in the blank.
Answer:
Sink
Question 23. The pressure at a given depth in a liquid is __________ proportional to the depth.
Fill in the blank.
Answer:
Directly
Question 24. The force of attraction between two masses is called __________ force.
Fill in the blank.
Answer:
Gravitational
Question 25. The force that opposes the relative motion of objects in contact is known as __________.
Fill in the blank.
Answer:
Friction
Question 26. The gravitational force between two objects decreases as the distance between them increases. (True/False)
Answer:
True
Question 27. The weight of an object is the same on Earth and the Moon. (True/False)
Answer:
False
Question 28. An object will float in a fluid if its density is less than the density of the fluid. (True/False)
Answer:
True
Question 29. Pascal’s principle is used in hydraulic brakes. (True/False)
Answer:
True
Question 30. The center of mass of a body always lies within the material of the body. (True/False)
Answer:
False
Question on Match the Columns
Unmatched Columns – Questions
| Column A | Column B |
|---|---|
| (i) Universal Law of Gravitation | (a) Acceleration due to Earth’s gravity |
| (ii) Free Fall | (b) Weight is proportional to mass |
| (iii) Difference between Mass and Weight | (c) Upward force exerted by fluids |
| (iv) Buoyancy | (d) Mass constant, weight varies with gravity |
| (v) Acceleration due to Gravity (g) | (e) Force between two masses |
| (vi) Archimedes’ Principle | (f) Objects float or sink based on density |
Matched Columns – Answer
| Column A | Column B |
|---|---|
| (i) Universal Law of Gravitation | (e) Force between two masses |
| (ii) Free Fall | (a) Acceleration due to Earth’s gravity |
| (iii) Difference between Mass and Weight | (d) Mass constant, weight varies with gravity |
| (iv) Buoyancy | (c) Upward force exerted by fluids |
| (v) Acceleration due to Gravity (g) | (b) Weight is proportional to mass |
| (vi) Archimedes’ Principle | (f) Objects float or sink based on density |
