Studied by 2 peopleLight
An electromagnetic wave that travels in straight lines; a form of energy
Medium
Any physical substance through which energy can be transferred
Radiation
A method of energy transfer that does not require a medium, the energy travels at the speed of light
Electromagnetic Wave
a wave that has both electric and magnetic parts, does not require a medium, and travels at the speed of light
Visible Light
Electromagnetic waves that are visible to the human eye
Electromagnetic Spectrum
The classification of electromagnetic waves by energy
Visible Spectrum
The continuous sequence of colours that make up white light
Luminous
An object that emmits light
Non-Luminous
An object that reflects light and does not produce it
Incandescence
Light produced from heat
Electrical Discharge
Producing light by passing an electric current through a gas
Phosphorescence
An object absorbs UV light and emmits it slowly
Flourescence
An object absorbs UV light and refelcts it immediately
Chemiluminescence
The emission of light without heat from a chemical reaction
Bioluminescence
The production of light by means of a chemical reaction in an organism
Tribioluminescence
Producing light through scraping crystals together
LED (Light-Emitting Diode)
Light produced when a current runs through a semi-conductor
Laser
Emits a focused beam of one wavelength of light
Reflection
The bouncing back of light when it hits a surface it cannot pass through
First Law of Reflection
The angle of incident is equal to the angle of reflection
Second Law of Reflection
The incident ray, the normal, and the reflected ray lie in the same plane
Incident Ray
The ray that comes from an object and strikes a surface
Reflected Ray
The ray that is reflected off of a surface
Angle of Incidence
The angle between the incident ray and the normal (θi)
Angle of Reflection
The angle between the reflected ray and the normal (θr)
Plane Mirror
A mirror with a flat surface
SALT of a Plane Mirror
Same, Upright, Behind Mirror, Virtual
Concave Mirror
A mirror with a surface that curves inward
Principle Axis
The line passing through the centre of curvature and the vertex
Centre of Curvature
The centre of the sphere from which the mirror is made.
Vertex
The point in the middle of a mirror where the principle axis meets the mirror
Focus
The point at which parallel lines converge after reflecting off a concave mirror
SALT for a Concave Mirror (Beyond C)
Smaller, Inverted, Between F & C, Real
SALT for a Concave Mirror (Between C & F)
Bigger, Inverted, Beyond C, Real
SALT for a Concave Mirror (At C)
Same Size, Inverted, At C, Real
SALT for a Concave Mirror (At F)
No Image
SALT for a Concave Mirror (In Fron of F)
Bigger, Upright, Behind Mirror, Virtual
Incident ray parallel to the principle axis...
...reflects through the focus
Incident ray passing through the focus...
...reflects parallel to the principle axis
Incident ray passing through C...
...reflects back on itself
Incident rays striking the vertex...
...reflect at an equal angle with the principle axis
Convex Mirror
A mirror with a surface that curves outward
SALT for a Convex Mirror
Smaller, Upright, In Front of F, Virtual
Refraction
The bending or change in the speed and direction of light when in travels from one medium to another
Refracted Ray
The ray that is bent as it enters a new medium
Angle of Refraction
The angle between the refracted ray and the normal (θR)
Light bends _____ the normal when it enters a denser medium
Towards
Index of Refraction
The ratio of the speed of light in a vacuum to the speed of light in a medium
Light bends _____ the normal when it enters a less dense medium
Away from
Total Internal Reflection (TIR)
When light reflects at the barrier between two mediums instead of refracting
Critical Angle
The θi that results in the θR being exactly 90 degrees
Conditions for TIR
The first medium has a higher index and the θi is larger than the critical angle
Applications for TIR
Diamonds, fibre optic cables, prisms
Retro-Reflectors
An optical device in which the emergent ray is parallel to the incident ray
Lens
A transparent object with at least one curved side, causing light to refract
Converging Lens
A lens with a thick middle and thin edge, causes parallel rays to converge
Diverging Lens
A lens with a thin middle and thick edge, causes parallel rays to diverge
Secondary Focus
The focus on the opposite side of a lens’ image
2F/2F’
The point double the distance of the focal length
Converging lenses have _ F values
Positive
Diverging lenses have _ F values
Negative
Chromatic Aberration
Happens in thick lenses, different colours refract differently
SALT for a Converging Lens (Beyond 2F')
Smaller, Inverted, Between 2F and F, Real
SALT for a Converging Lens (At 2F')
Same Size, Inverted, At 2F, Real
SALT for a Converging Lens (Between 2F' and F’)
Larger, Inverted, Beyond 2F, Real
SALT for a Converging Lens (At F')
No Image
SALT for a Converging Lens (In Front of F')
Larger, Upright, Same Side, Virtual
SALT for a Diverging Lens
Smaller, Upright, Same Side/Closer to Lens, Virtual
Camera
Uses a converging lens to create a real image on a sensor
Focusing a Camera
Change the position of the lens to bring the image into focus
Zoom on a Camera
Adjust lenses to change the focal point
Movie Projector
Use a converging lens to magnify an image onto a big screen
Magnifying Glass
An object within the focus of a converging lens forms a magnifyed virtual image
Compound Microscope
Uses two converging lenses; objective lense creates a real image and the eyepiece lens creates a virtual image
Refracting Telescope
Like a microscope but the object is distant
Cornea
On the front of an eye; clear tissue that refracts light
Iris
The coloured part of the eye
Pupil
Where light enters the eye
Lens (eye)
Inside the eye, refracts light onto the retina
Cilliary Muscles
Open and close the iris to let more or less light into the eye
Vitreous Humour
Fluid in the middle of the eyeball
Aqueous Humour
Fluid in front of the lens
Retina
The area on the back of an eyeball where the image is formed
Optical Nerve
Takes the image to the brain
Rods
Sense monochromatic light
Cones
Sense coloured light
Myopia
Light focuses in front of the retina
Hyperopia
Light focuses behind the retina
Presbyopia
Caused by age; the lens cannot accomidate for nearby objects
Astygmatism
Incorrectly shped eyeball; only some light focuses
Note 
Flashcard (83)