Physics Quiz
Physics explains how matter, energy and forces behave. The quiz covers motion, force, energy, electricity, light and units with questions that test concepts and simple calculations.
What this quiz covers
- Motion and forces
- Work and energy
- Electricity
- Light and waves
Study tip: Always write the units next to your numbers; many mistakes are caught by checking units.
Questions, answers and explanations
1. What is the SI unit of force?
- Joule
- Newton
- Watt
- Pascal
Answer: Newton
The SI unit of force is the Newton (N).
2. Who discovered the law of gravity?
- Albert Einstein
- Isaac Newton
- Galileo Galilei
- Nikola Tesla
Answer: Isaac Newton
Sir Isaac Newton proposed the law of universal gravitation.
3. What is the SI unit of energy?
- Newton
- Joule
- Watt
- Volt
Answer: Joule
Energy is measured in joules (J).
4. Which instrument is used to measure electric current?
- Voltmeter
- Ammeter
- Thermometer
- Barometer
Answer: Ammeter
An ammeter is used to measure electric current.
5. What is the speed of light in vacuum?
- 3 × 10⁶ m/s
- 3 × 10⁷ m/s
- 3 × 10⁸ m/s
- 3 × 10⁹ m/s
Answer: 3 × 10⁸ m/s
The speed of light in vacuum is approximately 3 × 10⁸ m/s.
6. What is the SI unit of power?
- Joule
- Newton
- Watt
- Volt
Answer: Watt
Power is measured in watts (W).
7. Which force keeps the planets in orbit around the Sun?
- Magnetic Force
- Frictional Force
- Gravitational Force
- Electrostatic Force
Answer: Gravitational Force
The Sun's gravitational force keeps the planets in orbit.
8. Which of the following is a scalar quantity?
- Velocity
- Force
- Acceleration
- Mass
Answer: Mass
Mass has magnitude only, so it is a scalar quantity.
9. What is the SI unit of temperature?
- Celsius
- Kelvin
- Fahrenheit
- Joule
Answer: Kelvin
The SI unit of temperature is Kelvin (K).
10. Which law states that every action has an equal and opposite reaction?
- Newton's First Law
- Newton's Second Law
- Newton's Third Law
- Law of Gravitation
Answer: Newton's Third Law
Newton's Third Law states that every action has an equal and opposite reaction.
11. What is the SI unit of pressure?
- Newton
- Pascal
- Joule
- Watt
Answer: Pascal
Pressure is measured in pascals (Pa).
12. Which instrument is used to measure atmospheric pressure?
- Thermometer
- Ammeter
- Barometer
- Voltmeter
Answer: Barometer
A barometer measures atmospheric pressure.
13. Which form of energy is stored in a stretched spring?
- Kinetic Energy
- Heat Energy
- Elastic Potential Energy
- Electrical Energy
Answer: Elastic Potential Energy
A stretched or compressed spring stores elastic potential energy.
14. What is the acceleration due to gravity on Earth?
- 8.9 m/s²
- 9.8 m/s²
- 10.8 m/s²
- 12.8 m/s²
Answer: 9.8 m/s²
The average acceleration due to gravity is approximately 9.8 m/s².
15. Which color of visible light has the longest wavelength?
- Blue
- Green
- Yellow
- Red
Answer: Red
Red light has the longest wavelength in the visible spectrum.
16. Which device converts electrical energy into mechanical energy?
- Generator
- Electric Motor
- Transformer
- Battery
Answer: Electric Motor
An electric motor converts electrical energy into mechanical energy.
17. Which planet has the strongest gravitational pull in our Solar System?
- Earth
- Mars
- Jupiter
- Saturn
Answer: Jupiter
Jupiter has the strongest gravity among all the planets in the Solar System.
18. The SI unit of frequency is:
- Volt
- Hertz
- Ohm
- Tesla
Answer: Hertz
Frequency is measured in hertz (Hz).
19. Sound cannot travel through:
- Air
- Water
- Steel
- Vacuum
Answer: Vacuum
Sound requires a material medium and cannot travel through a vacuum.
20. Which law is represented by the formula F = ma?
- Newton's First Law
- Newton's Second Law
- Newton's Third Law
- Law of Gravitation
Answer: Newton's Second Law
Newton's Second Law states that Force = Mass × Acceleration (F = ma).