Lets have a look at some of the top MCQ questions from chapter 7 Work, Energy, and Simple Machines. These questions will help you to revise the chapter properly.
Lets have a look at some of the important points of the chapter –
- Work is force multiplied by displacement in force direction.
- SI unit of work is joule (J).
- Work done is zero without displacement.
- Perpendicular force causes zero work done.
- Work can be positive or negative.
- Energy is the capacity to do work.
- Work done equals change in energy.
- Mechanical energy includes kinetic and potential energy.
- Kinetic energy depends on mass and velocity.
- Kinetic energy formula is K = ½mv².
- Potential energy is stored due to position.
- Gravitational potential energy equals mgh.
- Higher objects possess greater gravitational potential energy.
- Mechanical energy remains conserved without external forces.
- Simple machines reduce effort and increase convenience.
35 MCQ Questions for Class 9 Science: Chapter 7 Work, Energy, and Simple Machines
Question 1. What is the SI unit of work?
a) Newton
b) Joule
c) Watt
d) Pascal
Answer:
b) Joule — Unit derived from force × distance.
Question 2. Work done equals:
a) Force × Time
b) Mass × Velocity
c) Force × Displacement
d) Force × Acceleration
Answer:
c) Force × Displacement — Only displacement along force matters.
Question 3. One joule equals:
a) 1 N/m
b) 1 N × 1 m
c) 1 kg × 1 m
d) 1 N × 1 s
Answer:
b) 1 N × 1 m — Direct SI definition.
Question 4. Work done is zero when:
a) Force is large
b) Velocity is high
c) Displacement is zero
d) Mass is zero
Answer:
c) Displacement is zero — No movement, no work.
Question 5. Pushing a rigid wall results in:
a) Positive work
b) Negative work
c) Maximum work
d) Zero work
Answer:
d) Zero work — Wall does not move.
Question 6. Work done is zero when force and displacement are:
a) Parallel
b) Opposite
c) Perpendicular
d) Equal
Answer:
c) Perpendicular — No displacement along force.
Question 7. Carrying a box horizontally involves:
a) Positive work
b) Negative work
c) Zero work by lifting force
d) Infinite work
Answer:
c) Zero work by lifting force — Force acts vertically.
Question 8. Work is positive when force and displacement are:
a) Same direction
b) Opposite direction
c) Perpendicular
d) Random
Answer:
a) Same direction — Force helps motion.
Question 9. Goalkeeper stopping a ball does:
a) Positive work
b) Negative work
c) Zero work
d) Maximum work
Answer:
b) Negative work — Force opposes motion.
Question 10. Work is a:
a) Vector quantity
b) Scalar quantity
c) Tensor quantity
d) None
Answer:
b) Scalar quantity — Has magnitude only.
Question 11. Energy is defined as:
a) Force applied
b) Rate of work
c) Capacity to do work
d) Momentum possessed
Answer:
c) Capacity to do work — Fundamental definition.
Question 12. Work-energy theorem states:
a) Work = Force
b) Work = Power
c) Work = Change in energy
d) Energy = Velocity
Answer:
c) Work = Change in energy — Core chapter concept.
Question 13. SI unit of energy is:
a) Watt
b) Joule
c) Newton
d) Pascal
Answer:
b) Joule — Same as work.
Question 14. Which is NOT a form of energy?
a) Chemical
b) Sound
c) Thermal
d) Density
Answer:
d) Density — Property, not energy.
Question 15. Electrical bulb converts electrical energy into:
a) Light energy
b) Sound energy
c) Nuclear energy
d) Magnetic energy
Answer:
a) Light energy — Main useful output.
Question 16. Mechanical energy depends on:
a) Motion or position
b) Colour
c) Shape only
d) Temperature only
Answer:
a) Motion or position — Includes KE and PE.
Question 17. Energy due to motion is called:
a) Potential energy
b) Chemical energy
c) Kinetic energy
d) Sound energy
Answer:
c) Kinetic energy — Motion-related energy.
Question 18. Kinetic energy formula is:
a) mgh
b) mv
c) ½mv²
d) ma
Answer:
c) ½mv² — Depends on velocity squared.
Question 19. If velocity doubles, kinetic energy becomes:
a) Double
b) Triple
c) Four times
d) Half
Answer:
c) Four times — Velocity squared relation.
Question 20. Kinetic energy depends directly on:
a) Mass
b) Velocity squared
c) Both a and b
d) Height
Answer:
c) Both a and b — Both appear in formula.
Question 21. A stationary object has kinetic energy:
a) Maximum
b) One joule
c) Zero
d) Infinite
Answer:
c) Zero — Velocity equals zero.
Question 22. Potential energy is energy due to:
a) Motion
b) Position or deformation
c) Sound
d) Heat
Answer:
b) Position or deformation — Stored energy.
Question 23. Stretched rubber band stores:
a) Kinetic energy
b) Potential energy
c) Sound energy
d) Light energy
Answer:
b) Potential energy — Due to deformation.
Question 24. Compressed spring possesses:
a) Potential energy
b) Zero energy
c) Sound energy
d) Nuclear energy
Answer:
a) Potential energy — Stored by compression.
Question 25. Potential energy of Earth-ball system increases with:
a) Temperature
b) Height
c) Colour
d) Density
Answer:
b) Height — Higher position, more energy.
Question 26. Gravitational potential energy formula is:
a) mv²
b) ma
c) mgh
d) mg
Answer:
c) mgh — Near Earth’s surface.
Question 27. Potential energy unit is:
a) Joule
b) Newton
c) Watt
d) Pascal
Answer:
a) Joule — Same as work.
Question 28. Mechanical energy equals:
a) KE − PE
b) KE × PE
c) KE + PE
d) PE only
Answer:
c) KE + PE — Total mechanical energy.
Question 29. During free fall, potential energy:
a) Increases
b) Remains constant
c) Decreases
d) Becomes zero instantly
Answer:
c) Decreases — Converts into kinetic energy.
Question 30. During free fall, kinetic energy:
a) Decreases
b) Increases
c) Remains zero
d) Remains constant
Answer:
b) Increases — Speed continuously increases.
Question 31. In ideal free fall, mechanical energy:
a) Increases
b) Decreases
c) Remains conserved
d) Becomes zero
Answer:
c) Remains conserved — KE gain equals PE loss.
Question 32. A pendulum demonstrates:
a) Nuclear energy
b) Energy conservation
c) Density changes
d) Chemical reaction
Answer:
b) Energy conservation — KE and PE interchange.
Question 33. At pendulum’s highest point, it has:
a) Maximum KE
b) Equal KE and PE
c) Maximum PE
d) Zero PE
Answer:
c) Maximum PE — Velocity becomes zero.
Question 34. At pendulum’s lowest point, it has:
a) Maximum KE
b) Maximum PE
c) No energy
d) Equal KE and PE
Answer:
a) Maximum KE — Speed is highest.
Question 35. Simple machines mainly help by:
a) Creating energy
b) Destroying energy
c) Reducing effort
d) Increasing mass
Answer:
c) Reducing effort — Makes work convenient.
10 True and False Questions for Chapter 7 Work, Energy, and Simple Machines
Question 1. Work done is zero if displacement is zero. (True/False)
Answer:
True
Question 2. Carrying a box horizontally involves positive work by the lifting force. (True/False)
Answer:
False
Question 3. The SI unit of both work and energy is joule. (True/False)
Answer:
True
Question 4. Negative work is done when force opposes displacement. (True/False)
Answer:
True
Question 5. Kinetic energy depends only on mass. (True/False)
Answer:
False
Question 6. A stretched spring stores potential energy. (True/False)
Answer:
True
Question 7. Gravitational potential energy decreases with increasing height. (True/False)
Answer:
False
Question 8. During free fall, potential energy converts into kinetic energy. (True/False)
Answer:
True
Question 9. Mechanical energy is the sum of kinetic and potential energies. (True/False)
Answer:
True
Question 10. Simple machines create energy while performing work. (True/False)
Answer:
False
10 Fill in the Blanks Questions for Chapter 7 Work, Energy, and Simple Machines
Question 1. Work done by a force equals force multiplied by __________.
Answer:
Displacement
Question 2. The SI unit of work is the __________.
Answer:
Joule
Question 3. An object possessing the capacity to do work has __________.
Answer:
Energy
Question 4. The energy possessed by a moving object is called __________ energy.
Answer:
Kinetic
Question 5. The kinetic energy of an object is proportional to the square of its __________.
Answer:
Velocity
Question 6. The energy stored due to position or deformation is called __________ energy.
Answer:
Potential
Question 7. Gravitational potential energy near Earth’s surface is given by __________.
Answer:
mgh
Question 8. During free fall, potential energy converts into __________ energy.
Answer:
Kinetic
Question 9. The sum of kinetic and potential energy is called __________ energy.
Answer:
Mechanical
Question 10. Simple machines help perform tasks with less __________.
Answer:
Effort
Question on Match the Columns
Unmatched Columns – Questions
| Column A | Column B |
|---|---|
| (i) Work-Energy Theorem | (a) Energy due to motion |
| (ii) Kinetic Energy | (b) Force × displacement |
| (iii) Potential Energy | (c) Energy due to position or deformation |
| (iv) Mechanical Energy | (d) Work done equals change in energy |
| (v) Work Done | (e) Sum of kinetic and potential energies |
| (vi) Conservation of Mechanical Energy | (f) Total mechanical energy remains constant |
Matched Columns – Answer
| Column A | Column B |
|---|---|
| (i) Work-Energy Theorem | (d) Work done equals change in energy |
| (ii) Kinetic Energy | (a) Energy due to motion |
| (iii) Potential Energy | (c) Energy due to position or deformation |
| (iv) Mechanical Energy | (e) Sum of kinetic and potential energies |
| (v) Work Done | (b) Force × displacement |
| (vi) Conservation of Mechanical Energy | (f) Total mechanical energy remains constant |
Related Class 9 Physics Chapters
Work and energy join force with motion. Revise both sides:
- How Forces Affect Motion MCQs – no force, no work done.
- Describing Motion Around Us MCQs – needed for kinetic energy sums.
- Earth as a System MCQs – energy flow on a planet scale.
Practise the numericals
Next chapter: Chapter 8 – Journey Inside the Atom
See all chapters: MCQ Questions for Class 9 Science – All 13 Chapters
