# Interference and Diffraction Flashcards

Diffraction

The bending of waves as they pass through a gap

When waves pass through a gap similar to their wavelength

Diffraction is bigger

Central Maximum

Biggest band of wave in a diffraction grating

Subsidiary Maxima

Narrower fainter bands of waves in a diffraction grating

minimum (diffraction gratings)

dark bands in a diffraction grating where destructive interference has happened

Superposition

Constructive interference

interference maxima

Constructive interference

Path difference = (whole number, n) x wavelength

Path difference must be whole numbers

Interference minima

Destructive interference

Path difference = (whole number, n) x 0.5wavelength

Path difference must be odd numbers of half wavelengths

Path difference

The difference between the length of two wave’s path

Young’s Double Slit Experiment

Passed wavelength through two slits to show interference of light

Interference

The combination of two waves to form constructive or destructive interference

Diffraction grating equation

(number of lines per mm) x wavelength = (grating spacing) x sin(angle)

d = 1/N