Diffraction (SQA National 5 Physics): Revision Note

Diffraction

• Diffraction occurs when a wave meets a gap or an obstacle and the wave spreads out

Diffraction of a wave

• Diffraction is greatest when the wavelength is the same size as the gap, or larger than the gap

• As the gap gets bigger, the amount of diffraction decreases

Diffraction and gap size

• Diffraction can also occur when waves pass an edge

 Diffraction around an edge

Wavefronts

• Wavefronts are a diagrammatic representation of waves as if viewed from above

• The lines represent the peaks of the wave

• Therefore, the distance between the lines is equal to the wavelength