Chapter-4 Forces — Online MCQ Test
PHYSICS · Grade 10 · IGCSE cambridge
Practice Chapter-4 Forces with a free chapter-wise online MCQ test.
This chapter covers: The effects of forces Hooke's law friction circular motion and turning effects including moments..
AI-generated questions from basic to board-exam level, with instant results and explanations.
Chapter-4 Forces — Important Questions & Answers
What does Hooke's law state about the relationship between force and extension in a spring?
- A. Force is inversely proportional to extension
- B. Force is directly proportional to extension, up to the limit of proportionality
- C. Force is equal to the extension in all cases
- D. Force causes permanent deformation immediately
Answer: B. Force is directly proportional to extension, up to the limit of proportionality
Hooke's law states F = kx, where force is directly proportional to extension within the elastic limit.
Hooke's law states F = kx, where force is directly proportional to extension within the elastic limit.
The spring constant of a spring is 200 N/m. What is the extension when a force of 50 N is applied?
- A. 0.25 m
- B. 0.5 m
- C. 2 m
- D. 4 m
Answer: A. 0.25 m
Using F = kx, extension x = F/k = 50/200 = 0.25 m.
Using F = kx, extension x = F/k = 50/200 = 0.25 m.
A student applies a force of 30 N to a door handle at a perpendicular distance of 0.8 m from the hinge. What is the moment produced?
- A. 24 N·m
- B. 37.5 N·m
- C. 3.75 N·m
- D. 26.8 N·m
Answer: A. 24 N·m
Moment = Force × perpendicular distance = 30 × 0.8 = 24 N·m.
Moment = Force × perpendicular distance = 30 × 0.8 = 24 N·m.
A car of mass 1000 kg moves in a horizontal circular path of radius 50 m at constant speed of 10 m/s. What is the centripetal force required?
- A. 2000 N
- B. 1000 N
- C. 5000 N
- D. 500 N
Answer: A. 2000 N
Centripetal force F = mv²/r = (1000 × 10²)/50 = 100,000/50 = 2000 N.
Centripetal force F = mv²/r = (1000 × 10²)/50 = 100,000/50 = 2000 N.
A material is stretched beyond its elastic limit and does not return to its original length when the force is removed. Which of the following best explains this phenomenon?
- A. The spring constant has increased permanently
- B. Hooke's law no longer applies because permanent deformation has occurred
- C. The material has gained elastic potential energy
- D. The force applied was insufficient to cause any change
Answer: B. Hooke's law no longer applies because permanent deformation has occurred
Once the elastic limit is exceeded, the material undergoes plastic deformation and does not obey Hooke's law; permanent deformation occurs as atomic bonds are broken or rearranged.
Once the elastic limit is exceeded, the material undergoes plastic deformation and does not obey Hooke's law; permanent deformation occurs as atomic bonds are broken or rearranged.