GRADE 12: WAVES, SOUND AND LIGHT
Section	Sub-section
Huygens' Principle	Introduction
Doppler effect with sound	Introduction Moving source, stationary listener General case Blood flow rates measurements
Doppler effect with light	Introduction Red shifts and blue shifts
Colour	Dispersion The visible spectrum Primary and complementary colours The colour of objects
2D and 3D wavefronts	Principle of superposition of waves Diffraction Interference Interference effects with light Interference of light by a double slit Shock waves
The wave nature of matter	The de Broglie hypothesis The wavelength of electrons
The electron microscope	General principles of electron microscopy The scanning electron microscope (SEM) The transmission electron microscope (TEM) Differences between TEM and SEM