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Year 9 Science — Mirrors and lenses

Tell concave from convex for both mirrors and lenses, use the laws of reflection to find an angle, and say which of them gathers a beam and which spreads it.

Name: ________________________

  1. 1.What does the image in a convex mirror look like, whatever the distance to the object?

    • a) Erect and smaller than the object
    • b) Erect and larger than the object
    • c) Inverted and smaller than the object
    • d) Inverted and the same size as the object

  2. 2.How does a concave lens differ from a convex one to look at?

    • a) It is the same thickness throughout
    • b) It is not transparent
    • c) It is thicker at the edges than in the middle
    • d) It is thicker in the middle than at the edges

  3. 3.The laws of reflection were worked out with a plane mirror. Which mirrors do they hold for?

    • a) Plane and concave mirrors, but not convex ones
    • b) Plane, concave and convex alike
    • c) Plane mirrors and nothing else
    • d) Curved mirrors, but not plane ones

  4. 4.Parallel beams of light fall on each of these. Sort them by what happens to the beams afterwards.

    Groups: Converges the beam · Diverges the beam

    • Convex lens
    • Convex mirror
    • Concave mirror
    • Concave lens

  5. 5.Sunlight is directed onto a sheet of paper with a concave mirror, and the paper is moved until a small bright spot forms. What happens next, and why?

    • a) The spot spreads out, because a concave mirror scatters light
    • b) The paper cools down, because the mirror has taken the heat out of the light
    • c) Nothing happens, because reflected light carries no heat
    • d) The paper can start to burn, because the mirror has concentrated the sunlight onto that point

  6. 6.The angle between the normal and the incident ray has a three-word name. What is it?

  7. 7.Why is a convex mirror, rather than a plane one, fitted as a vehicle's side-view mirror?

    • a) It shows a much wider area of the road behind
    • b) It shows the traffic behind the right way up, which a plane mirror cannot
    • c) It shows the traffic behind at a larger size
    • d) It is cheaper to make than a plane mirror of the same size

  8. 8.You are handed a magnifying glass. Which kind of lens is it?

    • a) A convex lens
    • b) A concave lens
    • c) A spherical mirror
    • d) A plane lens

Answer key — Year 9 Science — Mirrors and lenses

  1. 1. a) Erect and smaller than the object
  2. 2. c) It is thicker at the edges than in the middle
  3. 3. b) Plane, concave and convex alike
  4. 4. Concave mirror → Converges the beam; Convex lens → Converges the beam; Convex mirror → Diverges the beam; Concave lens → Diverges the beam
  5. 5. d) The paper can start to burn, because the mirror has concentrated the sunlight onto that point
  6. 6. angle of incidence
  7. 7. a) It shows a much wider area of the road behind
  8. 8. a) A convex lens