Phase Difference Flashcards
What is phase difference?
The separation of two points on a wave as a fraction of the wavelength expressed as an angle in radians
What can be said about the energy transferred to the wave?
Energy is directly proportional to the amplitude
What happens to the depth as amplitude is increased?
Depth increases
How can a value of k be determined?
Experimentally only
What are travelling waves?
Waves that oscillate as well as travel forward
When are stationary waves formed?
When a reflected travelling wave overlaps the original wave and produces a waveform that looks ‘stationary’ (superposition)
What is the disturbance?
The height of the combined wave
What are coherent waves?
Waves with a constant phase difference
What is perfectly constructive interference?
When there is a phase difference of a whole multiple number of 2 pi
What is physically happening to the waves in perfectly constructive interference?
Peak meets peak and trough meets trough
What happens in perfectly destructive interference?
There is a phase difference of (n+1/2)x2pi
What physically happens when there is perfectly destructive interference?
Peak meets trough and trough meets peak
What is the amplitude of a wave that has undergone perfect constructive interference?
The amplitude of the combined wave is 2A
What is the amplitude of a wave that has undergone perfectly destructive interference?
Amplitude of combined wave 0m
What are nodes and anti nodes on a stationary wave diagram?
Nodes are on the outside of the wave
Antinode is the distance between the peak and trough
What is the first harmonic also known as?
The fundamental
What kind of waves have to be used for an interference pattern to be produced?
Two or more coherent waves
What is the equation for the path difference for constructive interference?
PD= n(wavelength)
What is the equation to find is used to find the path difference for destructive interference(minima)?
PD=(n+1/2)(wavelength)
What does D stand for?
Distance between the slits and screen
What does d stand for?
Separation distance of the slits
What is produced if both waves used are coherent?
A maxima
How can the optical path difference be found?
Optical path difference(OP)=geometric path difference(GP) x refractive index (n)
What is the path difference when the two rays are exactly the same length?
0
How can optical path difference be calculated?
OPD=GP x n
What equation is used to calculate OPD at a minima?
OPD=(m+1/2) x wavelength
What is the equation used to calculate the OPD at a maxima?
OPD=m x wavelength
