# Chapter 38: Diffraction

Diffraction is the result of interference when a wave passes through an opening or edge. Diffraction effects are easier or harder to see depending on the wavelength of the wave and the size of a given opening. The physical principle behind diffraction is the same as that of interference (see Chapter 37): the superposition of waves. In order to observe the effects of diffraction, slits or gratings must be of a size comparable to the wavelength of the light.

# Table of Contents

## Illustrations

- Illustration 38.1: Single Slit Diffraction.
- Illustration 38.2: Application of Diffraction Gratings.

# Explorations

- Exploration 38.1: Modeling Diffraction from a Slit.
- Exploration 38.2: Diffraction Grating.

# Problems

- Problem 38.1: Rank waves in ripple tanks by slit width.
- Problem 38.2: Rank waves in ripple tanks by slit width.
- Problem 38.3: Determine the slit width.
- Problem 38.4: Wavelength of light through a single slit.
- Problem 38.5: Wavelength of light through a diffraction grating.
- Problem 38.6: Number of slits per millimeter in diffraction grating.