IB Physics Topic 3 Definitions
This page contains our IB Physics definitions for topic 3. By learning each one of these definitions, you will fully cover the content for IB Physics 'Wave Behaviour'.
amplitude
It is the maximum displacement of the particle from its mean position
Analyzer
It is a polarizer that detects the angle of polarization
Angular frequency
It is the angle oscillated per unit time
Antinode
It is a point a maximum amplitude in a standing wave
Blue shift
It is the increase in frequency of light due to the moving closer of an observer or source
Boundary conditions
These are the conditions that must be present at the edges of a system for a standing wave to be formed. Also called resonant modes
Complete constructive interference
It is the interference of in phase waves leading to a summation into a larger amplitude wave
Complete destructive interference
It is the interference of out of phase waves leading to a summation into a zero amplitude wave
compression
It is an area of high particle density in a longitudinal wave
Constructive interference
It is interference that increases the displacement of both waves
Critical angle
It is the angle at which there is no refraction and complete reflection back into the medium
Destructive interference
It is interference that decreases the displacement of both waves
Diffraction
It is the spreading of waves after passing through apertures, resulting in an energy distribution in the geometric shadow region
Diffuse reflection
It is the reflection of several rays from a rough surface
displacement
It is the net distance an object has travelled from its starting point in a direction
electromagnetic wave
It is a transverse wave with an electrical and magnetic component
First harmonic
It is the resonant mode with the lowest frequency
frequency
It is the number of oscillations in one second
Fringes
It is the pattern of light and dark regions formed by diffraction
Geometric shadow region
It is the region not in line with the aperture
In phase waves
These are waves with a phase difference of zero or path difference of nλ
Intensity
It is the energy per unit area
Interference
It is the superposition of two waves of the same type when they come together
longitudinal wave
It is a travelling wave where the oscillation is parallel to the direction of energy transfer
Monochromatic source
It is a source that emits one frequency of light
Node
It is a point at rest in a standing wave
oscillations
They are the continual movement of an object around a fixed point, creating a cyclical path the object travels to constantly interchange between kinetic and potential energy
Out of phase waves
These are waves with a phase difference of 180° or path difference of (n+1/2)λ
Perfect reflection
It is the reflection of a single ray from a smooth surface
period
It is the time it takes to complete one oscillation
phase difference
It is the measure of the alignment of two oscillations
Plane of vibration
It is the plane of the electric field of an electromagnetic wave and the direction of wave propagation
Plane-polarized light
It is light with a fixed plane of vibration
Polarizer
It is a device that transforms unpolarized light into plane-polarized light
rarefaction
It is an area of low particle density in a longitudinal wave
ray
It represents the direction of travel of wave energy
Red shift
It is the decrease in frequency of light due to the moving away of an observer or source
Reflection
It is the scattering of a wave when it hits a surface
Refraction
It is the change in direction of a wave when it crosses from one medium to another due to a change in wave speed
Simple harmonic motion
It is the motion of an object where its acceleration is proportional to and towards its displacement
Single-slit diffraction
It is the spreading of a wave through a single aperture
Standing wave
It is a wave whose spatial pattern remains constant whilst the amplitude changes
Total internal reflection
It is the complete reflection of a wave back into the medium
transverse wave
It is a travelling wave where the oscillation is perpendicular to the direction of energy transfer
travelling wave
It is an oscillating wave that transfers energy through a medium via the movement of particles in the direction of the wave at a constant speed
Unpolarized light
It is light with a randomly varying plane of vibration
Wave pulse
It is a non-sinusoidal disturbance of a medium that propagates as a half of a wave
Wavefront
It represents the moving together of oscillation points
wavelength
It is the distance one oscillation travels
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