Superposition and Interference Flashcards
Define Superposition.
The interaction between more than one wave. They can be moving in the same direction or in opposite directions.
What happens if 2 waves are travelling along a phase? How does this link in with the amplitude?
Two waves travelling along in phase, each with a amplitude of ‘A’
What happens if 2 waves meet?
If these waves meet, their amplitudes will be added together and we get one overall wave with an amplitude of ‘2A’.
What happens if two waves meet at an angle and are out of phase?
Their amplitudes would cancel each other out and there particles in the wave would rest on the equilibrium!
Define Constructive Interference.
This is when two waves add up.
Define Destructive Interference.
This is when two waves cancel each other out.
How do you identify if the waves are creating a constructive or destructive interference?
if both waves are on the same side as the equilibrium it is constructive.
If they are on different sides it is destructive interference.
Define Diffraction.
The bending of waves passing through a gap or around a corner.
How do you reach the maximum diffraction?
When the wavelength is the same size as the gap.
What is a diffraction grating?
A plate with many closely spaced parallel slits.
What does the diffraction grating slits cause?
It cause the light to diffract as it passes through, which produces widely spaced interference patterns.
As a result of the superposition of waves from the many slits.
The more slits, the more interference.
What is the diffraction grating equation?
nλ = dsinθ
d = slit spacing (equivalent to 1 / number of slits per m). n = order of the image (how many bright fringes outwards) λ = wavelength of light θ = the angle of diffraction of the light ray
