As Waves

Front 1

Wavelength

Back 1

the distance between 2 successive points on a wave which are in phase with one another

Front 2

Amplitude

Back 2

the maximum displacement of the particle from its equilibrium position

Front 3

Displacement

Back 3

distance moved by the particle from its equilibrium position

Front 4

Period

Back 4

time taken for a particle on the wave to complete one oscillation

Front 5

Rarefraction

Back 5

a region where the particles are further apart. (Low pressure)

Front 6

Frequency

Back 6

the number of complete oscillations that pass through a given point in 1 second. Units: Hertz(Hz)

Front 7

Compression

Back 7

a region where particles are close to one another. (High pressure)

Front 8

Phase difference (φ)

Back 8

tells us how much a particle (or wave) is in front or behind another particle (or wave)

Front 9

Reflection

Back 9

the change in direction of a wavefront at an interface between two different media so that the wavefront returns into the medium from which it originated

Front 10

Refraction

Back 10

the change in direction of a wave passing from one medium to another caused by its change in speed

Front 11

Transverse wave

Back 11

the vibrations are perpendicular to the direction of the energy transfer

Front 12

Longitudinal waves

Back 12

the displacement of the medium is parallel to the propagation of the wave

Hint 12

Along the direction if energy transfer

Front 13

Constructive interference

Back 13

When two waves meet in such a way that their crests line up together

Front 14

Destructive interference

Back 14

the crest of one wave meets the trough of another, and the result is a lower total amplitude

Front 15

Node

Back 15

a point along a standing wave where the wave has minimum amplitude

Front 16

Antinode

Back 16

the position of maximum displacement in a standing wave system

Front 17

Standing wave

Back 17

The superposition of two progressive waves with the same frequency (wavelength), moving in opposite directions

Hint 17

also known as stationary waves

Front 18

Fundamental frequency

Back 18

lowest possible frequency standing wave that can fit on the string

Hint 18

1st harmonic

Front 19

1st overtone

Back 19

1st harmonic, 1 full wavelength

Front 20

Superposition

Back 20

When two waves meet they overlap and interact. Sometimes they add to make a wave bigger, sometimes they cancel each other out, and often it's a combination of both

Front 21

Polarisation

Back 21

the process by which the oscillations are made to occur in one plane only

Hint 21

Can only happen for transverse waves

Front 22

Refractive index, n

Back 22

Measures how much a material slows down lift

Front 23

Critical angle

Back 23

the angle of incidence at which the angle of refraction is 90°

Front 24

Angle of incidence

Back 24

the angle between an incident ray and the normal (perpendicular to the material)

Front 25

Angle of refraction

Back 25

The angle between a refracted ray and the normal.

Front 26

Phase

Back 26

A measurement of position of a certain point along the wave

Front 27

Diffraction

Back 27

The way waves spread it as they come through a narrow gap or go around obstacals

Front 28

Coherent

Back 28

two wave sources are perfectly coherent if they have a constant phase difference and the same frequency

Front 29

Monochromatic

Back 29

All the light has the same wavelength (and frequency)

Front 30

Fringe spacing

Back 30

The distance from the centre of one minimum to the centre of the next minimum (or max to max)

Front 31

Modal broadening

Back 31

Light rays enter at different angled so take different paths. Longer path= slower

Hint 31

Modal dispersion, stopped by single mode fibre

Front 32

Material broadening

Back 32

Light consists of different wavelengths that travel at different speeds in the fibre

Hint 32

Material dispersion, stopped by using monochromatic light

Front 33

Pulse broadening

Back 33

When the signal is sent down it becomes braided at the other end causing overlap and confuse the signal

Front 34

Absorption

Back 34

The signal is absorbed by the material causing a loss of amplitude so signal is reduced

Front 35

Optical fibre repeater

Back 35

boosts and regenerates signal which reduces degradation caused by absorption and dispersion

Front 36

Cladding

Back 36

Lowers refractive index in optical fibres and prevent​ scratches which let out light, allows total internal reflection

Front 37

Core

Back 37

Transmission medium for em waves to progress

Hint 37

By total internal refraction

Front 38

Electromagnetic waves

Back 38

Transverse, travel in magnetic and electric fields, vibrations are perpendicular the direction of energy tansfere

Front 39

Central maximum

Back 39

Brightest part of the pattern

Hint 39

In single slut light diffraction

Front 40

Intensity

Back 40

Power per unit area

Front 41

Fringe spacing

Back 41

The distance from the centre of one minimum to the next

Front 42

Incident ray

Back 42

An incident ray is a ray of light that strikes a surface