Refraction of Light

index of refraction of air:

1.00

index of refraction of water:

1.33

index of refraction of crown glass:

1.52

what is the Lens Equation?

1/f=1/do + 1/di

index of refraction if diamond:

2.42

the critical angle boundary from diamond to air is:

25 degrees

point on the principle axis that is twice as far from the vertical axis as the focal point is

2F point

the critical angle boundary from water to air is:

48.6 degrees

the critical angle boundary from glass to water is:

61 degrees

number that indicates the number of times slower light will travel in a certain material than it would in a vacuum.

Index of Refraction

a carefully molded piece of material that refracts light rays in order to form an image

Lens

what is the magnification equation?

M= hi/hi = -di/do

as light travels from a more optically dense medium to a less optically dense medium, it bends away from the normal line

Total Internal Reflection

shows the direction of light as it approaches the boundary

angle of incidence

shows the direction of light as it cross the boundary

angle of refraction

coin underwater appears larger because the image formed in water is closer to the observer than the image formed in air

apparent depth

a liqud in the eye that refracts rays

aqueous humor

if light travels from a higher index of refraction to lower, it bends (toward/away) from the normal line, causing light to speed up

away

if light travels from a more dense medium to a less dense medium, light moves (toward/away) from the normal line

away

when drawing ray diagrams: draw a ray from the top of the object, through the _____ of the lens where the ______ and _______ ____ meet.

center principle and vertical axis

fingerlike muscles attached to the lens that change its shape and thus its focal length

ciliary muscles

a type of diverging lens where both side cave in and curve in the same direction

concave meniscus

what are the two types of lenses?

converging and diverging

incident rays that are parallel to the principle axis all converge at the focal point after refracting through the lens - thick across the middle and thinner at upper and lower edges

converging lens

what kind of lens are projectors, cameras, and the eye

converging lens

a type of converging lens where both sides bulge out and curve in the same direction

convex meniscus

exterior covering of the eye

cornea

for TIR to occur, the angle of incidence must be larger than the _____ ____

critical angle

smallest angle of incidence fro TIR to occur, occurs with large angles of incidence, yields an angle of refraction of 90 degrees

critical angle

incident rays that are parallel to the principle axis diverge out from the direction of the focal point once they pass through the lens - thin across middle and thick at upper and lower edges

diverging lens

a type of diverging lens where both sides cave in

double concave

a type of converging lens where both sides bulge out

double convex

distance from the focal point to the vertical axis

focal length

ray diagram: incident ray travels through the ___ ___ to the vertical axis and refracts ____ to the principle axis

focal point - parallel

since lenses are transparent, they allow light to pass through from either side, so it creates two possible ____ ____

focal points

during TIR, the light is trapped inside the medium with the (higher/lower) index of refraction

higher

______ ______ will always be the same because it is the diameter of the eye ball

image distance

what is the boundary between two mediums where refraction occurs called?

interface

when the angle of incidence gets too large, no light crosses the boundary into the less dense medium and the light is ______ ____ ____

internally reflected back

if m or hi is negative, the image is _____

inverted

colored part of the eye, controls how much light comes in

iris

a light ray is bent toward the normal line when it enters a medium in which light travels slowly; bent away from the normal line when it enters a medium in which light travels faster

law of refraction

converging lens controlled by ciliary muscles

lens

more/less optically dense means faster light travel

less

when looking at objects in distance, lens is thinner and has a _____ focal length

longer

if m is greater than 1, the image is _____

magnified

More/less optically dense means slower light travel

more

the higher the index of refraction the (more/less) optically dense

more - which means slower light travel

for TIR to occur, light must be traveling from a (more/less) optically dense medium, to a (more/less) optically dense medium

more to less large index of refraction --> small index of refraction

a diverging lens has a ______ focal length - this means the rays appear to be coming from the focal point in front of the lens

negative

this line is drawn perpendicular to the boundary at the point of incidence

normal line

properties of the medium, this determines the speed of light

optical density

flexible, coated, strands of glass that utilize TIR to channel light

optical fibers

ray diagram: incident ray travels ____ to the principle axis, meets the vertical axis, and ____ through the lens through the focal point

parallel - refracts

a type of diverging lens where one side caves in and the other is flat

plano concave

a type of converging lens where one side is flat and the other bulges out

plano convex

ALWAYS draw this ray through the center of the lens where the ____ and _____ _____ meet

principle and vertical axis meet

imaginary horizontal line through the center of the lens

principle axis

the path of light is refracted at an interface that is reversible

principle of reversibility

circular opening, large in dim light, and small in bright light

pupil

light passes through and the image is formed behind the lens

real image

if m is less than 1, the image is..

reduced

as the angle of incidence gets larger, so does the angle of _______

refraction

bending of a light wave as it passes across the boundary separating two media

refraction

when drawing ray diagrams: top of the object, parallel to the principle axis, the ray _______ and goes through the ____ ____ on the opposite side

refracts focal point

when drawing ray diagrams: ray goes through the focal point, to the center of the lens (vertical axis) then it ____ parallel to the ____ ____

refracts principle axis

receptor of image that sends optic signals to the brain

retina

when looking at near objects, lens is thick, has a ____ focal length

shorter

with a converging lens, the more sharply curved the lens is, the (shorter/longer) the focal length

shorter

the critical angle will be smaller when the speed is light is (faster/slower)

slower

refraction is caused by a change in the ______ ___ _____

speed of light

where does refraction occur?

the boundary between two mediums

for ray diagrams, light is now transmitted ____ the lens and _____

through and refracts

light rays strike the fiber at an angle that is bigger than the critical angle so it undergoes ______ ______ ______

total internal reflection

if light goes from a lower index of refraction to higher, it bends (toward/away) from the normal line, giving it a more direct path

toward

if light is going from a less dense medium to a more dense medium, the light travels (toward/away) from the normal line

toward

optical fibers are used to ___ ____ as pulses of light produced by tiny lasers

transmit information

if m or hi is positive, the image is _________

upright

imaginary vertical line that cuts the lens into equal halves

vertical axis

light doesn't pass through and the image is formed in front of the lens

virtual image

with a diverging lens, the type of image will always be...

virtual, upright, and reduced

with a converging lens, the type of image formed depends on ...

where the object is

EYE: focal length will change depending on...

whether objects are near of far