Lesson T4.2.1

T4.2.1 Light waves and the speed of light Quiz: KS3 Physics, Unit 4

20 questions

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Lesson T4.2.1, Light waves and the speed of light: 20 multiple choice questions for the KS3 Physics (National Curriculum), Unit 4: Waves, written with Revision Ninja.

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The 20 questions

  1. What is the approximate speed of light in a vacuum?

    • 3 000 m/s
    • 3 000 000 000 m/s
    • 300 000 000 m/s
    • 330 m/s
  2. What can light waves travel through that sound waves cannot?

    • Air
    • Glass
    • A vacuum
    • Water
  3. Which wave property is shared by both light and water waves?

    • Acoustic pressure
    • Need for a medium
    • Longitudinal motion
    • Refraction
  4. Roughly how long does it take for sunlight to reach Earth?

    • 1 day
    • 1 hour
    • 8 minutes 20 seconds
    • 1 second
  5. What does a light-year measure?

    • Speed
    • Brightness
    • Distance
    • Time
  6. Which common medium slows down light more than air?

    • Glass
    • Empty void
    • Outer space
    • Vacuum
  7. Why does starlight take years to reach Earth?

    • Vast distance
    • Slow wave speed
    • Heavy particles
    • Magnetic drag
  8. How long does light take to travel 1.5 × 10¹¹ m in a vacuum?

    • 500 seconds
    • 50 seconds
    • 300 seconds
    • 1500 seconds
  9. How does the speed of light in air compare to a vacuum?

    • Much slower
    • Zero
    • Twice as fast
    • Almost the same
  10. What type of wave is visible light?

    • Longitudinal mechanical
    • Transverse sound
    • Longitudinal electromagnetic
    • Transverse electromagnetic
  11. How does starlight travel through space to reach our eyes?

    • Through a vacuum
    • Via optical fibres
    • Through the air
    • Using sound waves
  12. What happens to the speed of light as it enters glass?

    • It speeds up
    • It stops entirely
    • It slows down
    • It stays constant
  13. Which medium allows light to travel at the maximum possible speed?

    • Air
    • Vacuum
    • Water
    • Glass
  14. What type of wave is an electromagnetic wave?

    • Transverse wave
    • Sound wave
    • Mechanical wave
    • Longitudinal wave
  15. What distance does light travel in a vacuum in 2 seconds?

    • 6 × 10⁸ m
    • 1.5 × 10⁸ m
    • 3 × 10⁸ m
    • 9 × 10⁸ m
  16. Which phenomenon demonstrates light transferring energy to a surface?

    • Gravity pulling down
    • Sunlight warming surfaces
    • Sound echoing back
    • Magnets attracting iron
  17. What observation proves that light does not need air to travel?

    • Sunlight reaching Earth
    • Wind blowing trees
    • Stars sounding loud
    • Echoes in caves
  18. What unit is typically used for measuring enormous distances between stars?

    • Light year
    • Kilometre
    • Metre
    • Astronomical mile
  19. How long does light take to travel 300,000 km in a vacuum?

    • 2 seconds
    • 300 seconds
    • 1 second
    • 0.5 seconds
  20. Why does a lightning flash appear before the thunder is heard?

    • Sound travels faster
    • Light travels faster
    • Sound is heavier
    • Light is louder

All KS3 Physics quizzes