24 terms
Waves (OCR Physics A)
Key words and definitions for the Waves section of Unit G482 of OCR Physics A (AS Level).
Created by Rob Cowen, Head of Physics (www.cowenphysics.com).
phase difference
the fraction of a cycle (measured in degrees) between the oscillations of two particles
path difference
the difference in the distances travelled by two waves from coherent sources at a particular point
superposition
when two or more waves meet, the resultant displacement is equal to the sum of the displacements of each wave
interference
when two waves superpose at a point and there is a change in overall displacement
coherence
constant phase difference between waves
displacement
distance moved from equilibrium of a point on a wave
amplitude
maximum displacement
wavelength
the distance between two adjacent peaks and troughs
period
the time taken for one complete oscillation of a particle
frequency
number of wavelengths passing a point per unit time
speed of a wave
distance travelled by the wave per unit time
progressive wave
a transfer of energy as a result of oscillations
stationary wave
a wave which stores energy in pockets
longitudinal wave
displacement of particles is parallel to direction of energy transfer
transverse wave
displacement of particles is perpendicular to direction of energy transfer
reflection
the bouncing back of a wave from a circuit
refraction
the change in direction of a wave as it crosses an interface between two materials where its speed changes
diffraction
wavefronts spread out after passing through a gap or around an obstacle
intensity
power per unit area
plane polarised wave
a transverse wave that vibrates in one plane only
constructive interference
when two waves reinforce to give increased amplitude
destructive interference
when two waves cancel to give reduced amplitude
node
where the amplitude is always zero
antinode
where the amplitude of the standing wave takes the maximum possible value