2.2.3 Refraction of Light

• Materials with a higher refractive index bend light more.


  True
• Steps to describe Snell's Law

  1️⃣ Define the formula for Snell's Law

  2️⃣ Identify each variable in the formula

  3️⃣ Explain the effect of each variable on refraction
• Larger angles of incidence result in more bending
• Match the variable with its meaning in Snell's Law:

  n_1 ↔️ Refractive index of the first medium

  θ_1 ↔️ Angle of incidence

  n_2 ↔️ Refractive index of the second medium

  θ_2 ↔️ Angle of refraction
• Materials with higher refractive indices slow light more.

  True
• The critical angle $\theta_{c}$ is the angle of incidence at which total internal reflection occurs and is given by \sin^{ - 1}\left(\frac{n_{2}}{n_{1}}\right)
• Total internal reflection occurs when the angle of incidence is greater than the critical angle.
• In the critical angle formula, $n_{1}$ represents the refractive index of the first medium.
• Any light ray striking the glass-air boundary at an angle greater than 41.8° will undergo total internal reflection.
• Telescopes use lenses with different refractive indices.
• What is the refraction of light?

  Bending of light
• What is the angle of incidence?

  Angle light strikes boundary
• What is the formula for Snell's Law?

  $n_{1} \sin \theta_{1} =$$n_{2} \sin \theta_{2}$
• When light travels from air to water, it bends towards the normal.


  True
• What is Snell's Law used to describe?

  Refraction of light
• What does the refractive index measure?

  Light slows in a material
• Match the material with its approximate refractive index:

  Vacuum ↔️ 1.0

  Air ↔️ 1.0003

  Water ↔️ 1.33

  Diamond ↔️ 2.42
• What is total internal reflection?

  Light reflected in the original medium
• What is the critical angle in total internal reflection?

  The incidence angle where reflection occurs
• The refractive index of the first medium is always greater than the refractive index of the second medium for total internal reflection to occur.


  True
• What are some practical applications of refraction?

  Spectacles, telescopes, rainbows, mirages
• What creates the colorful arcs in a rainbow?

  Refraction within water droplets
• The refractive index is the ratio of the speed of light in a vacuum to the speed of light in the medium
• A material's refractive index measures how much it slows down light
• In Snell's Law, \( \theta_1 \) represents the angle of incidence
• What does a higher refractive index indicate about light speed in a material?

  Light slows down more
• The formula for Snell's Law is n_{1} \sin \theta_{1} = n_{2} \sin \theta_{2}
• The refractive index $n$ is calculated using the formula \frac{c}{v}
• Under what conditions does total internal reflection occur?

  Higher to lower refractive index
• Total internal reflection occurs when light travels from a medium with a lower refractive index to one with a higher refractive index.

  False
• What is the formula for the critical angle?

  \theta_{c} = \sin^{ - 1}\left(\frac{n_{2}}{n_{1}}\right)</latex>
• What is the critical angle when light travels from glass ($n_{1} =$$1.5$) to air ($n_{2} =$$1.0$)?


  $41.8^\circ$
• Lenses in spectacles have the same refractive index regardless of the lens material.

  False
• Mirages are created by light bending due to temperature gradients in the air.

  True