3.7 Diffraction

• What is diffraction?

  Bending of waves
• Huygens' Principle treats each point on a wavefront as a source of secondary wavelets.


  True
• Single-slit diffraction creates a pattern with a broad central maximum
• Arrange the features in a table to compare single-slit and diffraction grating diffraction:

  1️⃣ Number of slits: Single vs. Multiple parallel slits

  2️⃣ Pattern: Broad central maximum vs. Sharp, narrow bright lines

  3️⃣ Intensity: Decreases with fringe order vs. Concentrated at principal maxima

  4️⃣ Uses: Investigating wave behavior vs. Spectroscopy, light filtering
• Narrower slits or apertures lead to more diffraction of waves.

  True
• What is Huygens' Principle used to explain?

  Wave front propagation
• Diffraction is the bending of waves as they encounter obstacles or pass through openings.openings
• What happens to wave fronts when they encounter an obstacle or opening?

  They spread out
• Match the diffraction type with its feature:

  Single-Slit Diffraction ↔️ Broad central maximum

  Diffraction Grating Diffraction ↔️ Sharp, narrow bright lines
• Longer wavelengths experience more diffraction
• Huygens' Principle treats each point on a wavefront as a source of spherical secondary wavelets.


  True
• How do secondary wavelets propagate according to Huygens' Principle?

  Spherically
• Longer wavelengths can bend more around obstacles, leading to more diffraction
• Longer wavelengths lead to more diffraction
• In single-slit diffraction, there is only one slit
• What happens to the intensity in single-slit diffraction as fringe order increases?

  Decreases
• Longer wavelengths bend more around obstacles.


  True
• Sound diffracts significantly when the wavelength is much larger than the obstacle size.


  True
• Match the feature with its corresponding wave type:

  Air, water, solids ↔️ Sound

  Air, vacuum, water ↔️ Light
• Holography creates 3D images using diffracted light.


  True
• In Young's Double Slit Experiment, diffraction ensures light covers a wider area
• Diffraction occurs when waves encounter obstacles or pass through openings
• What are the two primary types of diffraction?

  Single-slit and diffraction grating
• Diffraction grating diffraction produces sharp, narrow bright lines called principal maxima.


  True
• Which wavelength experiences more diffraction: longer or shorter?

  Longer wavelength
• Longer wavelengths and narrower slits both result in greater diffraction
• How do wave fronts propagate according to Huygens' Principle?

  Secondary wavelets
• Huygens' Principle states that each point on a wavefront acts as a source of secondary wavelets.


  True
• The envelope of secondary wavelets forms the new wave front
• How many slits are present in single-slit diffraction?

  One
• Why do narrower slits or apertures lead to more diffraction?

  Less space to propagate
• In Huygens' Principle, the original wave originates from a primary source
• Match the diffraction type with its pattern:

  Single-Slit Diffraction ↔️ Broad central maximum

  Diffraction Grating Diffraction ↔️ Sharp, narrow bright lines
• Narrower slits or apertures cause wavefronts to spread out more, resulting in greater diffraction.


  True
• Narrower slits result in more diffraction.


  True
• Diffraction gratings produce sharp, narrow bright lines.


  True
• Huygens' Principle treats each point on the wavefront as a source of secondary wavelets
• What determines the degree of sound diffraction?

  Wavelength relative to obstacle size
• The typical wavelength of sound ranges from 0.017 m to 17 m.
• Diffraction gratings are used in spectroscopy to separate light into its component wavelengths