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Boss quiz

10 questions on the whole topic. You get one try at each.

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  1. How does light travel?

    • Only through air
    • In straight lines
    • In curves
    • Only downwards

  2. Which of these can light do, but sound cannot?

    • Travel through a vacuum
    • Travel through air
    • Be reflected
    • Carry energy

  3. A ray hits a mirror with an angle of incidence of 40°. What is the angle of reflection?

    • 40°
    • 140°
    • 50°
    • 80°

  4. Where is the angle of incidence measured from?

    • The reflected ray
    • The ray box
    • The surface of the mirror
    • The normal

  5. A ray of light goes from air into glass at an angle. What happens to it?

    • It bends away from the normal
    • It stops at the surface
    • It goes straight on
    • It bends towards the normal

  6. What does a convex lens do to parallel rays of light?

    • Spreads them out
    • Splits them into colours
    • Reflects them back
    • Brings them together at a focus

  7. Which part of the eye detects light?

    • The pupil
    • The cornea
    • The retina
    • The lens

  8. Which colour of light does a prism bend the most?

    • Red
    • Yellow
    • Violet
    • Green

  9. A red apple is lit only by green light. What colour does it look?

    • Red
    • Black
    • Yellow
    • Green

  10. Frosted glass lets light through, but you cannot see clearly through it. Which word describes it?

    • Opaque
    • Reflective
    • Translucent
    • Transparent
Answers
  1. In straight lines. Light travels in straight lines. That is why we can draw it as rays.
  2. Travel through a vacuum. Light does not need particles to carry it. Sound does.
  3. 40°. The angle of reflection always equals the angle of incidence.
  4. The normal. Both angles are measured from the normal: the line at 90° to the mirror.
  5. It bends towards the normal. Light slows down in glass, so it bends towards the normal.
  6. Brings them together at a focus. A convex lens is thicker in the middle. It bends the rays towards each other.
  7. The retina. The image forms on the retina. Its cells send signals along the optic nerve to the brain.
  8. Violet. Violet is refracted the most and red the least. That is why the colours spread out.
  9. Black. The apple absorbs green light. There is no red light for it to reflect.
  10. Translucent. A translucent material lets some light through and scatters it.