Waves, superposition and refractive index Flashcards
What is a progressive wave
Wave carrying energy from one place to another - material is not transferred in the process
Describe transverse waves
Displacement perpendicular to the direction of energy transfer
Describe transverse waves
Displacement parallel to the direction of energy transfer
Define amplitude
Maximum possible displacement of the wave
Define wavelength
Distance between two repeating parts of a wave
Define time period
Time between two repeating parts of a wave
Define phase
Position of a certain point along a wave’s cycle
What is phase difference
When different waves are in the same position in space but in different parts of their cycle
How is a EM wave produced
Oscillation of perpendicular electric and magnetic fields
It stores energy within its field
What is used by scientists to accelerate charged particles to produce intense EM waves
A synchotron
What produces EM waves
Accelerating charged particles
What waves can be polarised
Transverse waves as they oscillate in all directions
When is a wave polarised
The wave is vibrating in only one direction
Define intensity
Measure of power per unit area
P.S: Intensity is a measure of it’s amplitude squared - directly proportional to it
Applications of polarisation
Sunglasses reduces glare with polarised light
Malu’s Law
Intensity at detector = Intensity of wave x cos^2(theta)
theta = angle of polariser
Stationary wave definition
When two progressive waves of the same frequency and amplitude but moving in opposite directions superpose
What are nodes
Places where waves maximally destructively interfere
What are antinodes
Places where waves maximally constructively interfere
Factors effecting resonant frequency
Longer the string - the lower the resonant frequency
The heavier the string - the lower the resonant frequency
The lower the tension on the string - the lower the resonant frequency
What is the resonant frequency
1st harmonic
