optics Flashcards
the branch of physics dealing with light and vision is called _____
optics
objects that are radiate light are ______
luminous
a _____ ______ is the distance that light travels in a vacuum in 1 year
light year
a lense or mirror curved outwards is called ______
convex
a ______ telescope enlarges the image with mirrors
reflecting
the ____ __ _______ is connected to the angle of _____ because both angles are exactly the same
angle of incidence
reflection
____ lenses are NOT similar to _____ lenses because one causes them to diverge
convex
concave
____ is connected to ____ because light travels faster through some substances than others making the image appear bent or ____
refraction
density
broken
____ are NOT similar to ___ because one reflects light and the other causes light to be refracted
mirrors
prisms
____ are connected to ____ light because these angled pieces of glass or crystals break light into a ____ of 7 colours
prisms
refracting
spectrum
true or false:
lenses can only converge light
false
true or false:
light travels in straight lines
true
true or false:
the study of optics deals with light and vision
true
true or false:
light travels in the vacuum of space
true
true or false:
refraction bends light
true
when light travels, it goes in straight lines. what creates a shadow?
the absence of light
this illustration demonstrates how light travels and is referred to as a? (blue arrows going down, being reflected as red arrows going straight up)
ray diagram
when light interacts with a substance, different things can happen to the light because of the type of material it is made of. what do Opaque materials do to light?
block
when a light bulb in a lamp receives electrical energy, it will produce a light. the term used to indicate that a light source produces light is?
luminous
this illustration demonstrates a type of reflection known as? (blue arrow going down, red arrows scattering everywhere after being reflected)
diffuse
when parallel rays of light hit the surface of this type of mirror, they are reflected back to a focal point in front of the mirror, the type of mirror that does this is called?
concave mirror
cosmetic mirrors, flashlights, reflecting telescopes, headlights on a car, are examples of practical applications for this mirror.
concave mirror
if an object is placed far away from the focal point in a concave mirror it will appear…
inverted & smaller
if an object is placed between the focal point in a concave mirror and the mirror itself, the image will appear…
upright & larger
when light is refracted, the angle of incidence increase, and the angle of refraction…
increases, depending on material
define Concave
- having outline or surface that curves inward
-interior of circle or sphere
2 types -plano concave lens
-Double concave lenses
define convex
- curved or rounded outwards
- exterior of sphere or circle
2 types - plano convex lens
- double convex lens
define reflection
-return of light or sound waves from surface
-action of bending or folding back
2 types -specular diffuse
- regular diffuse
define refraction
- deflection of straight path undergone by light ray or energy wave
- action of distorting an image by viewing through medium
parts of eye
-sclera -cornea -pupil -lens -iris -ciliary body -choroid -retina -optic nerve -conjunctiva -optic disc
define sclera
- white part of eye
- protects eyeball
STUDY DIAGRAMS
optics book - cross section of eye
cheat sheet (names and definition of angle(s)
How’d it go?
define cornea
- clear window at front of eye
- covers iris + pupil
define pupil
- black dot at center of eye
- opening where light enters
define lens
- acts like camera lens by focusing light onto retina at back of eye
define iris
- coloured part of eye
- surrounding pupil
- controls how much light enter eye by changing size of pupil
define ciliary body
- ring shaped tissue
- holds and controls movement of eye lens
- control shape of lens
define choroid
- between retina and sclera
- provides blood supply to eye
define retina
- light sensitive
- inner lining at back of eye
- 10 dif. layers of cells working together to detect light , turn it into electrical pulses
define optic nerve
- carries electrical pulses from retina to brain
define conjunctiva
- layers of mucus
- help keep outside of eye moist
define optic disc
- no rods or cones
- creates blind spot
- exit for ganglion cell axons leaving eye
name 2 types of light and all types of light in that category
Natural -sun & fire - Bioluminescence Artificial -incandescent - fluorescent - phosphorescent - chemiluminescent
define bioluminescence
- produced by organisms within bodies due to chemical reaction
define incandescent light 2 ex.
- objects super heated to such high temp.- emit light
- candle flame - light bulb-filament tungsten
define fluorescent light 2 ex.
- high energy particles absorb invisible light-light up bulb
- fluorescent light bulb - phosphor coating glows
define phosphorescent light 1 ex.
- light energy is absorbed from other source
- phos. particles give off light after light source is removed
- glow-in-the-dark items
define chemiluminescent light 1 ex.
- chemical reactions
- give off radiant light
- glow stick energy
define EMR. describe diagram
- light spectrum
- identified by wavelengths, frequencies, energy
- visible light is mixture of all colours of rainbow
1. Gamma 2. X-ray 3. UV 4. Visible light 5. Infrared 6. Micro waves 7. Radio waves - squiggly lines get shorter when going to gamma rays
- long wavy lines for radio waves
who was Pythagoras?
- Greek philosopher
- believed beams of light- from tiny particles
- eyes detected particles-allowed us to see object
who was Albert Michelson
- first person to measure speed of light
- calculated 3x10 (8 squared) m/s
speed of light & sound
light- 1 000 000 000 km/h
sound- 1200 km/h
light technologies include…
- Microscope - Telescope - Periscope - Binoculars - Fibre Optics - Camera - Prescription Contact lenses
- Laser - Movie projectors - overhead projectors
properties of light
- light travels in straight line
- light reflects (reflection)
- light refracts (refraction)
- light disperses (dispersion)
- light travels through a vacuum (does not require a medium; no particles involved
- light travels through objects to different angles
___ has the smallest refraction and ___ has the greatest. Can be seen due to the ___ through a prism
red
violet
dispersion
define frequency
- number of wavelength-pass in 1 seconds
- measured in hertz
high frequency short wavelength
low frequency long wavelength
define radio waves 2 ex.
-longest wavelength
- lowest energy
- lowest frequency
ex.
-radio
-inside bodies to diagnose illness
define microwaves 6 ex
-specific frequency that strongly absorbed by water molecules in food ex. - microwave ovens - microwaves -telecommunication -satellites -radio telescopes -radar remote sensing
define infrared waves 4 ex.
-infrared means below red
- also called heat radiation
ex.
-remote controls
-computer
-heat lamps
-motion sensors
define visible light spectrum
- continually detect by our eyes
- anything you can see, fluorescent light, led light
define ultraviolet light 2 ex.
-very energetic
ex.
-kill bacteria in water, food, & medical supplies
-sun, detect fingerprints
3 ex. of X rays
- x-ray
- security screening
- photograph teeth, bones, inside machines
define gamma rays 2 ex.
-highest energy & frequency
-results from nuclear reactions
-produced by the hottest regions of the universe
ex.
-nuclear explosion
-medical treatment
_____ energy radiation is more harmful to humans. the earths ___ is able to protect us from some of the more dangerous radiation in present in space.
higher
atmosphere
positive and negative effects to exposure from:
X-rays -Ultraviolet rays -radio waves
x-rays positive- good medical attention negative- over exposure=cancer Ultraviolet positive-treat jaundice in babies negative-skin cancer Radio waves positive- improved telecommunication negative- uncertain of long-term exposure
define transparent
- allows light to pass through freely
- only small amount of light absorbed or reflected
define Opaque
- prevents any lights from passing through
- only absorb light or reflect it
define translucent
- most light rays pass through
- scattered in all directions
light travels in straight lines, this is called ____
Rectilinear Propagation
incoming light ray is called the ___
incident light ray
an imaginary line that is perpendicular to the barrier is called the ___
normal
the angle formed by the incident ray and the normal is the ___
angle of reflection
applications of specular and diffuse reflection include:
- countertop surfaces
- furniture or car wax
- glazed vs. unglazed ceramics
- matte vs. glossy finish on photographs
law of reflection states the angle of __ equals the angle of ___
incidence
reflection
define plane mirrors 4 ex.
-image size is equal to object size
-image distance is equal to object distance
-image is upright
-image is virtual
-everything depending on position of object
ex.
-bathroom mirrors
-rear view mirrors
-dentist mirrors
-periscopes
define concave mirrors 7 ex.
-be smaller, larger or same size
-upright or inverted
- actual or virtual
ex.
-inside metal spoon
-spotlights
-overhead projectors
-flashlights
-car headlights
-light houses
-satellite dishes
define convex mirrors 3 ex.
-smaller than object
-image distance is smaller than object distance
-image is upright
-image is virtual
ex.
-safety mirrors on bus
-side view mirrors on vehicles
-disco balls
real vs. virtual images
real image formed-when reflected rays (not extended rays) meet located-in front of mirror -need screen to see real image virtual image formed-reflected rays are extended located-behind mirror
the ___ of a wave when it travels from one __ to another. the ___ ray is found in the second medium travelling in a different ___. the angle between the normal and the refracted ray is called the ___.
bending medium refracted direction angle of refraction
what happens as light travels from a less dense medium to as more dense medium?
ray bends towards the normal
what happens as light travels from a more dense medium to a less dense medium?
ray bends away from the normal
why is an object in water not where you think it is?
if light travels through 2 different mediums before it reaches your eyes, it doesn’t travel in a straight line. the object is not where your brain thinks it is.
lenses are usually made from __ or ___.
glass
plastic
define corrective lenses and the different kinds
nearsightedness- see objects close but not at a distance
lens used to correct-concave
farsightedness- see objects at a distance but not close up
lens used to correct- convex
what lens does a microscope use?
- 2 convex lenses with short focal points
- magnified 2x to increase enlargement-magnify
what lens do telescopes use, what are the 2 types of telescopes?
refracting- objective lens must be large as possible to view distant galaxies.
-lenses bend light to focus it
reflecting-concave mirror, plane mirror, & convex lenses to collect focus light from objects at a large distance
-most telescopes use this type
what lens does a camera use?
convex
what lens do binoculars use?
concave or convex
what lens do face shields use?
convex
what lens do magnifying glasses use?
convex
what lens do contact lenses use?
convex
what lens does flashlights use?
concave
what lens do eye glasses use?
concave or convex
the highest point of a wave is the ___ and the lowest is the ___.
crest
trough
matter in a ___ moves up and down perpendicular to the direction of the wave travels. the ___ of a wave describes the distance from one crest to another.
transverse wave
compression wave
the ___ of a wave describes the distance from highest point to the rest position.
amplitude
