NCERT Class 8 Science MCQ | Chapter 5: Exploring Forces
1. What is a force in science?
(A) A form of energy
(B) A push or pull resulting from the interaction of objects
(C) The speed of an object
(D) The mass of an object
Answer: (B) A push or pull resulting from the interaction of objects
2. Which of the following is an example of applying a force by pushing?
(A) Pulling a drawer
(B) Kicking a football
(C) Lifting a bag
(D) Stretching a rope by pulling
Answer: (B) Kicking a football
3. Which of the following is NOT an effect of force?
(A) Changing the speed of an object
(B) Changing the direction of motion
(C) Changing the shape of an object
(D) Changing the mass of an object
Answer: (D) Changing the mass of an object
4. A moving bicycle is stopped by applying brakes. What effect of force is demonstrated?
(A) Change in shape
(B) Change in mass
(C) Change in speed
(D) Change in colour
Answer: (C) Change in speed
5. When a batsman hits a moving ball and changes its direction, the force has changed the:
(A) Mass of the ball
(B) Direction of motion
(C) Temperature of the ball
(D) Size of the ball
Answer: (B) Direction of motion
6. What is the SI unit of force?
(A) Joule
(B) Pascal
(C) Newton
(D) Watt
Answer: (C) Newton
7. Which statement about force is correct?
(A) A force can act only when an object is moving
(B) A force always changes the mass of an object
(C) At least two objects must interact for a force to come into play
(D) A force can never change the shape of an object
Answer: (C) At least two objects must interact for a force to come into play
8. An object may remain at rest even when forces are acting on it because:
(A) No force can act on a stationary object
(B) The forces acting on it may balance each other
(C) The object has no mass
(D) Gravity stops acting on it
Answer: (B) The forces acting on it may balance each other
9. Which of the following is a contact force?
(A) Gravitational force
(B) Magnetic force
(C) Electrostatic force
(D) Muscular force
Answer: (D) Muscular force
10. Muscular force is produced due to:
(A) Movement of air
(B) Action of muscles in the body
(C) Attraction between magnets
(D) Earth’s gravity
Answer: (B) Action of muscles in the body
11. Which force causes a rolling ball on a flat surface to gradually slow down?
(A) Magnetic force
(B) Electrostatic force
(C) Frictional force
(D) Gravitational force only
Answer: (C) Frictional force
12. In which direction does friction act?
(A) In the same direction as motion
(B) Opposite to the direction of motion or attempted motion
(C) Always vertically upward
(D) Always vertically downward
Answer: (B) Opposite to the direction of motion or attempted motion
13. Why is friction generally greater on rough surfaces?
(A) Rough surfaces have no irregularities
(B) Irregularities of the two surfaces lock into each other more
(C) Rough surfaces have less contact
(D) Rough surfaces have no force acting on them
Answer: (B) Irregularities of the two surfaces lock into each other more
14. Why are aeroplanes, ships, boats, and high-speed trains given specific shapes?
(A) To increase their mass
(B) To reduce friction due to air or water
(C) To increase gravitational force
(D) To increase electrostatic force
Answer: (B) To reduce friction due to air or water
15. Which of the following is a non-contact force?
(A) Frictional force
(B) Muscular force
(C) Magnetic force
(D) Force applied by a hand
Answer: (C) Magnetic force
16. What happens when two like poles of magnets are brought close to each other?
(A) They attract
(B) They repel
(C) They become neutral
(D) They stop exerting force
Answer: (B) They repel
17. Which statement about electrostatic force is correct?
(A) It can act only between magnets
(B) It acts only when objects are touching
(C) A charged object can exert force on another object without contact
(D) It is always an attractive force
Answer: (C) A charged object can exert force on another object without contact
18. What happens when a plastic scale is rubbed with polythene and brought near small pieces of paper?
(A) The paper pieces are repelled immediately
(B) The paper pieces may be attracted towards the scale
(C) The paper pieces lose their mass
(D) Nothing happens
Answer: (B) The paper pieces may be attracted towards the scale
19. What happens when two balloons are rubbed with a woollen cloth and brought near each other?
(A) They attract each other
(B) They repel each other
(C) They become uncharged immediately
(D) They remain permanently attached
Answer: (B) They repel each other
20. Which statement about electric charges is correct according to the chapter?
(A) Like charges attract and unlike charges repel
(B) Like charges repel and unlike charges attract
(C) All charges attract each other
(D) Charges cannot exert force without contact
Answer: (B) Like charges repel and unlike charges attract
21. What is the gravitational force?
(A) The force with which a magnet attracts iron
(B) The force with which Earth attracts objects towards itself
(C) The force produced by rubbing two objects
(D) The force produced by muscles
Answer: (B) The force with which Earth attracts objects towards itself
22. Which statement about gravitational force is correct?
(A) It acts only when objects are touching
(B) It is always repulsive
(C) It is a non-contact force and is always attractive
(D) It acts only on magnetic materials
Answer: (C) It is a non-contact force and is always attractive
23. What is the weight of an object?
(A) The amount of matter in the object
(B) The gravitational force with which Earth pulls the object
(C) The volume of the object
(D) The density of the object
Answer: (B) The gravitational force with which Earth pulls the object
24. Which instrument is used to measure the weight of an object?
(A) Thermometer
(B) Spring balance
(C) Measuring cylinder
(D) Beam compass
Answer: (B) Spring balance
25. Which statement correctly describes mass and weight?
(A) Both mass and weight remain the same everywhere
(B) Mass changes from place to place, but weight remains constant
(C) Mass remains unchanged, while weight can vary from place to place
(D) Mass and weight are both measured in newtons
Answer: (C) Mass remains unchanged, while weight can vary from place to place
NCERT Class 8 Science MCQ | Chapter 5: Exploring Forces
Assertion–Reason Questions
Directions:
Choose the correct option:
(A) Both Assertion and Reason are true, and Reason is the correct explanation of Assertion.
(B) Both Assertion and Reason are true, but Reason is not the correct explanation of Assertion.
(C) Assertion is true, but Reason is false.
(D) Assertion is false, but Reason is true.
1. Assertion: A force can change the speed or direction of motion of an object.
Reason: A force is a push or pull resulting from the interaction of two or more objects.
Answer: (B)
2. Assertion: Friction is a contact force.
Reason: Friction comes into play when two surfaces are in contact and one surface moves or tries to move over the other.
Answer: (A)
3. Assertion: Like charges repel each other.
Reason: Two balloons rubbed in the same way acquire similar charges and move away from each other.
Answer: (A)
4. Assertion: The weight of an object can be different on different planets.
Reason: Weight depends on the gravitational force acting on the object, while the mass of the object remains unchanged.
Answer: (A)
5. Assertion: An object placed in a liquid can experience an upward force.
Reason: A liquid applies an upward force called upthrust or buoyant force on an object immersed in it.
Answer: (A)
