Chapter-5 Exploring Forces — Online MCQ Test
SCIENCE · Grade 8 · CBSE(NCERT)
Practice Chapter-5 Exploring Forces with a free chapter-wise online MCQ test.
This chapter covers: contact force - non-contact force - friction - gravity - electrostatic force - magnitude - direction.
AI-generated questions from basic to board-exam level, with instant results and explanations.
Chapter-5 Exploring Forces — Important Questions & Answers
Which of the following is an example of a contact force?
- A. Gravitational force
- B. Friction force
- C. Electrostatic force
- D. Magnetic force
Answer: B. Friction force
Friction is a contact force that acts between two surfaces in contact, whereas gravitational and electrostatic forces are non-contact forces.
Friction is a contact force that acts between two surfaces in contact, whereas gravitational and electrostatic forces are non-contact forces.
What is the SI unit of force?
- A. Kilogram
- B. Newton
- C. Joule
- D. Pascal
Answer: B. Newton
The SI unit of force is Newton (N), named after Sir Isaac Newton. One Newton is the force required to accelerate 1 kg of mass at 1 m/s².
The SI unit of force is Newton (N), named after Sir Isaac Newton. One Newton is the force required to accelerate 1 kg of mass at 1 m/s².
When a ball is rolling on the ground and gradually comes to rest, which force is primarily responsible for stopping it?
- A. Gravity
- B. Applied force
- C. Friction
- D. Magnetic force
Answer: C. Friction
Friction between the ball and the ground surface opposes the motion of the ball, causing it to gradually decelerate and come to rest.
Friction between the ball and the ground surface opposes the motion of the ball, causing it to gradually decelerate and come to rest.
If you push a heavy box across the floor, you must overcome friction. This friction depends on:
- A. Only the weight of the box
- B. Only the roughness of the floor
- C. Both the weight of the box and the roughness of surfaces in contact
- D. Only the speed at which you push
Answer: C. Both the weight of the box and the roughness of surfaces in contact
Friction depends on both the normal force (weight) pressing the surfaces together and the nature of the surfaces (roughness/smoothness).
Friction depends on both the normal force (weight) pressing the surfaces together and the nature of the surfaces (roughness/smoothness).
Which statement correctly compares contact and non-contact forces?
- A. Contact forces are always stronger than non-contact forces
- B. Non-contact forces require physical touching, while contact forces do not
- C. Contact forces require direct contact, while non-contact forces act at a distance
- D. Non-contact forces only affect lightweight objects
Answer: C. Contact forces require direct contact, while non-contact forces act at a distance
Contact forces (friction, normal force, applied force) require surfaces to touch, while non-contact forces (gravity, electrostatic, magnetic) act through space without direct contact.
Contact forces (friction, normal force, applied force) require surfaces to touch, while non-contact forces (gravity, electrostatic, magnetic) act through space without direct contact.