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11th grade Refraction and Snell's law worksheet

6 printable versionsChallenge Me10 questions · answer keyFree · no account

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Refraction and Snell's law

Grade 11 Science Worksheet - Challenge Me

NameDate

Circle the best answer, or write your answer on the line.

  1. Use n = 1.00 for air. What is the critical angle for light inside water (n = 1.333) meeting a surface with air, to 0.1°, Ari?

  2. Use n = 1.00 for air. What is the critical angle for light inside Plexiglas (n = 1.49) meeting a surface with air, to 0.1°, Esme?

  3. A ray inside water hits the surface at 60° to the normal. Water's critical angle is 48.6°. What happens, Jun?

    • It stops at the surface
    • It leaves into the air at 60° to the normal
    • All of it reflects back into the water

  4. How does an optical fiber carry light around a gentle bend, Kira?

    • Total internal reflection at its walls
    • Light bends smoothly to follow the fiber's curve
    • The fiber glows on its own

  5. Milo says light entering water from air bends away from the normal. Agree or disagree?

    • Agree: slower light bends away
    • Agree: water pushes light away
    • Disagree: it bends toward the normal

  6. Noah says a ray entering diamond from air bends away from the normal because diamond is so hard. Agree or disagree?

    • Agree: diamond speeds light up
    • Disagree: it bends toward the normal
    • Agree: hard materials push light away

  7. Pia says light going from air into water can be totally internally reflected. Agree or disagree?

    • Disagree: it needs a higher index to a lower one
    • Agree: any boundary can do it
    • Agree: water reflects light that way

  8. A material has an index of exactly 1.00, like a vacuum. How would a ray from a vacuum bend entering it, Ren?

    • Not at all
    • Away from the normal
    • Toward the normal

  9. Rays from air enter water and diamond at the same angle. In which is the ray closer to the normal, Tala?

    • Diamond
    • They are the same
    • Water

  10. How does a material's critical angle change as its index gets bigger, Zee?

    • It gets smaller
    • It stays at 90°
    • It gets bigger
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11th grade Refraction and Snell's law worksheet – printable
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About this worksheet

Refraction and Snell's law. Every version has 10 questions, and the answer key prints on the second page.

What your child will learn

  • I can use refractive indices from a sourced table (water 1.333, Plexiglas 1.49, diamond 2.417) to find light's speed, v = c ÷ n.
  • I can use Snell's law, n₁ sin θ₁ = n₂ sin θ₂, with angles from the normal, for light entering and leaving water, Plexiglas and diamond.
  • I can predict the bending: toward the normal entering a higher index, away from it leaving one, and none along the normal.
  • I can find critical angles, sin θc = 1 ÷ n, and explain total internal reflection in optical fibers and diamonds. I can also explain everyday refraction: a bent-looking straw, a raised-looking coin and a prism's colors.

Standard: none (TX, FL)

Words to know

refraction: Light bending as it crosses into a material where its speed changes

refractive index (n): How many times slower light is in a material: n = c ÷ v

Snell's law: n₁ sin θ₁ = n₂ sin θ₂

critical angle: The angle beyond which light reflects totally inside a material

total internal reflection: All light reflecting back inside at a boundary

Common mistakes

Your child multiplied by the index. Light slows in a material: v = c ÷ n.

Your child divided the angle by the index. Snell's law works with sines: sin θ₂ = sin θ₁ ÷ n₂ for light from air.

Your child measured the critical angle from the surface. Like every angle in Snell's law, it is measured from the normal.

Questions parents ask

What is the most common mistake with refraction and snell's law?

Your child multiplied by the index. Light slows in a material: v = c ÷ n.

Are these 11th grade science worksheets free to print?

Yes. All 6 printable versions at each level are free to print, with the answer key, and no account is needed.

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