3.4 Refraction, diffraction, and interference

• What is refraction defined as?

  The bending of light
• Total internal reflection occurs when light travels from a denser medium to a less dense medium.


  True
• Huygens' Principle explains how waves propagate and create wave fronts
• Refraction occurs because the speed of light changes in different materials.


  True
• Order the bending of light when entering a denser medium:

  1️⃣ Light enters a denser medium

  2️⃣ Light slows down

  3️⃣ Light bends towards the normal
• The formula for Snell's Law is $\frac{\sin\theta_{1}}{\sin\theta_{2}} =$$\frac{n_{2}}{n_{1}}$, where $\theta_{1}$ is the angle of incidence
• What happens to light when it enters a denser medium in terms of speed and angle?

  Slows down and bends towards the normal
• What is the formula to calculate the critical angle for total internal reflection?

  $\sin\theta_{c} =$$\frac{n_{2}}{n_{1}}$
• Total Internal Reflection occurs when light attempts to escape from a denser medium to a less dense medium.
• What law determines the critical angle for total internal reflection?

  Snell's Law
• When light meets the conditions for total internal reflection, it is completely reflected back into the denser medium.

  True
• Significant diffraction occurs when the wavelength $\lambda$ is comparable to the obstacle size d.
• What is the initial surface of a wave called in Huygens' Principle?

  Wavefront
• Match the medium with the relative speed of light:

  Air ↔️ High

  Water ↔️ Slower

  Glass ↔️ Slowest
• What law describes the relationship between angles of incidence and refraction?

  Snell's Law
• Total internal reflection occurs when the angle of incidence is greater than the critical angle.

  True
• Arrange the following factors affecting diffraction in order of their effect on the degree of diffraction, from most to least significant:

  1️⃣ Longer wavelength

  2️⃣ Smaller opening

  3️⃣ Larger obstacle
• The envelope of secondary wavelets in Huygens' Principle forms the new position of the wavefront.


  True
• According to Huygens' Principle, the envelope of secondary wavelets forms the new position of the wavefront
• Match the element of Huygens' Principle with its description:

  Wavefront ↔️ Initial surface of a wave

  Secondary Wavelets ↔️ Spherical waves from the wavefront

  Envelope ↔️ Tangent surface connecting wavelets

  Propagation ↔️ Movement of the wavefront
• Huygens' Principle is crucial for understanding diffraction and interference.
• Steps in Young's Double-Slit Experiment

  1️⃣ Light passes through two narrow slits

  2️⃣ Waves diffract from each slit

  3️⃣ Interference pattern is formed on the screen

  4️⃣ Bright and dark spots are observed
• In Young's Double-Slit Experiment, waves cancel each other out during destructive interference.
• Match the parameter in Young's Double-Slit equation with its description:

  $d$ ↔️ Distance between slits

  $\theta$ ↔️ Angle from central maximum

  $m$ ↔️ Order of the interference pattern

  $\lambda$ ↔️ Wavelength of the light
• Constructive interference occurs when waves are in phase, resulting in an integer multiple of 2π as their phase difference.
• What is the mathematical expression for the resulting amplitude from interference?

  $A =$$A_{1} +$$A_{2}$
• Refraction occurs because the speed of light changes in different materials.
• Snell's Law relates the angles of incidence and refraction to the refractive indices of the media.

  True
• What is refraction?

  Bending of light
• In Snell's Law, the ratio of sines of the angles is equal to the ratio of refractive indices


  True
• Match the scenario with its properties:

  Light entering a denser medium ↔️ $\theta_{2} < \theta_{1}$ and $n_{2} > n_{1}$

  Light entering a less dense medium ↔️ $\theta_{2} > \theta_{1}$ and $n_{2} < n_{1}$
• Total Internal Reflection requires the angle of incidence to be greater than the critical angle


  True
• Match the factor with its effect on diffraction:

  Wavelength ↔️ Longer wavelengths diffract more

  Opening/Obstacle Size ↔️ Smaller openings diffract more
• Huygens' Principle is crucial for understanding diffraction and interference


  True
• Arrange the types of interference in order of their resulting effect:

  1️⃣ Constructive Interference

  2️⃣ Bright spots on the screen

  3️⃣ Destructive Interference

  4️⃣ Dark spots on the screen
• In Young's Double-Slit Experiment, the distance between the slits is denoted by d
• What is the equation used to calculate the position of bright and dark spots in Young's Double-Slit Experiment?

  $d\sin\theta =$$m\lambda$
• Young's Double-Slit Experiment demonstrates the interference of light waves.

  True
• In destructive interference, waves cancel each other out, resulting in dark spots on the screen.
• What is the mathematical expression for the resulting amplitude in interference?

  A = A_{1} + A_{2}</latex>