Reflection & Refraction · seed 1 · A4, ink-friendly. The answer key prints on its own page for grown-ups.

Reflection and Refraction of Light

Science · Waves, Light & Sound · ages 11-12
Name ______________________   Date ____________

  1. When drawing a ray diagram for a flat mirror, where do you find the virtual image?

    • In front of the mirror, where the actual reflected rays spread apart
    • Behind the mirror, where backward extensions of reflected rays meet
    • On the mirror surface, where the incoming and reflected rays meet

  2. A ray of light hits a flat mirror, making a 25° angle with the normal. What angle does the reflected ray make with the normal?

    • 25°
    • 50°
    • 65°

  3. True or false: a flat mirror forms an image the same size as the object.

    Circle one:   True   False

  4. You look from above at a straw partly under water. Why can it look bent at the water's surface?

    • Light bends as it leaves the water, so the underwater part appears shifted
    • Water changes the straw's shape, so its underwater part is physically bent
    • Water changes the straw's colour, so its underwater part moves sideways

  5. A light ray enters glass from air at a slant to the normal. What happens to its speed and direction?

    • It speeds up and bends away from the normal
    • It slows down and keeps its original direction
    • It slows down and bends toward the normal

  6. A light ray passes from water into air at a slant to the normal. What happens to its speed and direction?

    • It slows down and bends toward the normal
    • It speeds up and bends away from the normal
    • It speeds up and keeps its original direction

  7. A ray from an underwater fish travels along the normal and passes into air. Tom draws it bending away from the normal in air. How should he correct its direction?

    • Its direction should bend toward the normal
    • Its direction should bend farther away from the normal
    • Its direction should stay along the normal

  8. A ray of light hits a flat mirror. The angle between the incident ray and the mirror's surface is 35°. What is the angle between the reflected ray and the normal, in degrees?

    Answer: ______________

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Answer key

For grown-ups. Fold this page away before handing over the rest.

Reflection and Refraction of Light W1-mt_PifbJOuXrG-s1

  1. Behind the mirror, where backward extensions of reflected rays meet · You extend the reflected rays backward behind the mirror; where they meet is where the virtual image appears to be.
  2. 25° · The law of reflection says the angle of reflection always equals the angle of incidence, both measured from the normal, so it's 25°.
  3. True · A flat mirror's image is the same size as the object. The statement is true.
  4. Light bends as it leaves the water, so the underwater part appears shifted · Light refracts as it leaves the water, so your eye traces it back along a straight line to a shifted position, making the straw look bent.
  5. It slows down and bends toward the normal · Light travels more slowly in glass than in air. Because the ray enters at a slant, it bends toward the normal.
  6. It speeds up and bends away from the normal · The ray crosses into air, where light travels faster than in water. At this slant, it bends away from the normal.
  7. Its direction should stay along the normal · A ray entering along the normal has a 0-degree incidence angle. It speeds up when it enters air, but its direction stays along the normal.
  8. 55 · The normal is 90° from the mirror's surface, so the angle from the normal is 90 - 35 = 55°. The reflected ray makes that same 55° angle on the other side.
Worksheet · LightMySky