Reflection, Refraction, Diffraction and Polarisation Flashcards
What is the term reflection?
When a wave changes direction at a boundary between two media, remaining in the original medium.
What is the term refraction?
When a wave changes direction as it changes speed, when it enters a new medium.
What is diffraction?
The spreading out of a wave front as it passes through a gap.
When does maximum diffraction occur?
When the gap the wave passes through is the same size as the wavelength of the incident wave.
What is polarisation?
When the oscillation of a wave is restricted to one place only - this type of wave is said to be plane polarised.
Why can’t longitudinal waves experience polarisation?
The direction of the energy transfer is already in one plane only.
What is the principle of superposition?
When two or more waves meet at a point, the resultant displacement of the wave at that point is equal to the sum of the displacements of the individual waves.
