Waves Flashcards
Absorption Spectrum
The frequencies at which a certain element absorbs photons at a higher rate as these frequencies correspond to the spacings between energy levels in the element’s atoms
Antinode
The point on a stationary wave where the incoming and reflected wave are in phase forming a maximum point
Coherence
Waves with the same frequency and constant phase difference
Constructive Interference
Interference when the two waves are in phase
If the two waves are both at their peak the addition of the two peaks becomes large
Converging Lens
A lens that takes a parallel set of light rays and causes them to meet at a point
Critical Angle
The angle of incidence when the angle of refraction is exactly 90 degrees
It is when the refracted ray travels along the boundary line
De Broglie Hypothesis
All particles have a wave-like nature and a particle-like nature
The wavelength of a particle is inversely proportional to the particle’s momentum
De-excitation
The movement of an electron from a high energy level to a lower energy level
Occurs in excited atoms over time and causes photons to be released
Destructive Interference
Interference when the two waves are in antiphase
When one wave is at a peak and one is at a trough their addition results in a minimum point
Diffraction
The spread of a wave as it passes through a gap or over an edge
Diverging Lens
A lens that takes a parallel set of light rays and causes them to travel away from each other and not meet
Electronvolt
The kinetic energy gained by one electron that is accelerated through a potential difference of 1 volt
Emission Spectrum
When a certain element’s atoms de-excite they move from one energy level to another with a specific energy gap between these levels
This creates a photon of that specific energy and it is the frequencies of these photons that make up the emission spectrum
Excitation
The movement of an electron from a low energy level to a higher energy level.
This occurs when another electron or photon transfers energy to an orbital electron causing it to move to a higher energy level
Focal Length
The distance from the centre of the lens to the focal point
Focal Point
The point at which rays of light passing through a lens converge
Intensity
The power transferred by a wave per unit area
Lens Power
The inverse of the focal length
Longitudinal Wave
A wave whose oscillations are parallel to the direction of energy transfer
Magnification
Object height / Image height
Node
The point on a stationary wave where the incoming and reflected wave are in antiphase forming a minimum point
Photoelectric Effect
When light of a high enough energy shone on a metal surface causes electrons to be emitted.
The electrons are given enough kinetic energy by the photons to overcome the attractive force of the ions in the metal.
Progressive Wave
A wave that transfers energy from one point to another
Pulse-Echo Technique
An ultrasound technique used for imaging of objects, notably in medical imaging.
Short pulses of ultrasound are sent through a medium and their reflections recorded
