Chapter 12: Superposition Flashcards
What is the Principle of Superposition?
It states that when waves meet, the actual displacement is the vector sum of the displacements of individual waves, and each wave proceeds as though no other waves exist
What is a stationary wave?
It is a wave that is formed from the superposition of waves that have equal amplitudes and frequency, and are travelling at the same speed in opposite directions over the same space. There is no propagation of energy along the wave, and a stationary wave is characterised by nodes and antinodes occurring at fixed positions
Particles at displacement antinodes/nodes ____ as ____ interference occurred at these points
Fill in the blanks for antinodes and nodes
Nodes: do not oscillate, destructive
Antinodes: oscillate with maximum amplitude, constructive
What are coherent sources?
They are sources with a constant phase difference
What is a constructive interference?
It is the reinforcing of 2 waves that meet in phase at a point
What is a destructive interference?
It is the cancelling out 2 waves that meet in antiphase at a point
Define interference
It is the result of the superposition of wavetrains from a finite number of coherent sources
What are the conditions for interference?
- The sources must be coherent
- The waves cannot be polarised in mutually perpendicular points
- The amplitudes of the waves must be similar
What is the formula for Young’s Double slit experiment?
λ = (ax)/D
a: Distance between slits
x: Average fringe separation
D: distance of slits from screen
What is the formula for Single Slit diffraction?
sinθ = λ/b
b: width of slit
What is Rayleigh’s criterion?
It states that two point source images can barely be resolved if the central maxima of one source falls on the first minima of the other
θ = λ/b
What is the formula for diffraction grating?
dsinθ = nλ
d: separation
n: nth order maxima
