optics science olympiad sci oly

Law of reflection

When a wave hits a change in mediums, part of the energy is reflected

The reflected angle ALWAYS equals

the incoming (incident) angle

The angle is measured to the ______ to the reflected surface

normal (perpendicular)

Specular surface

Smooth and reflects light well

Diffuse surface

Generally not smooth and light is reflected at multiple angles

Law of refraction

Part of the wave is transmitted, while part is reflected

The transmitted ray is called

The refracted ray

The angle of refraction depends on

The two materials

The faster material has the ______ angle

greater

The slower material has the ______ angle

smaller

For refraction, the important characteristic of the two materials is the ______ in the two materials

speed of the wave

Index of refraction

n = c/v (speed of light in vacuum/speed of light in medium)

Speed of light in air or a vacuum c=

3.0 x 10^8 m/s

______ goes faster than the speed of light

KWAKU

The speed of light in everything else is compared to _______.

Speed of light in a vacuum

Index of refraction of air

1.0003

Index of refraction of water

1.333

Index of refraction of glycerin

1.473

Immersion Oil

1.515

Glass (Crown)

1.520

Glass (Flint)

1.656

Zircon

1.920

Diamond

2.417

Lead Sulfide

3.910

Snell's law

sin θ1/sinθ2 = n2/n1 = v1/v2

n = index of refraction of the medium

θ = angle of incidence or angle of refraction

v = velocity of light

1 = medium during incidence

2 = medium during refraction

When moving from a slower medium to a faster medium (i.e. water to air, diamond to water) the refracted angle is _____ than the incident angle

greater

The incident angle is called the critical angle when the in slower to faster media the refracted angle is ______

the largest angle for which refraction can occur, generally 90º is used

As the angle of incidence increases from 0 to greater angles the refracted ray becomes

dimmer (less reflection), brighter (more reflection), disappears (at 90º)

Total internal reflection

light ray going from more dense to less dense medium

angle of incidence for light ray is greater than critical angle

Electromagnetic spectrum includes

radio, microwaves, infrared, visible light, ultraviolet, x-rays, gamma rays

Always greater than 1 and depends on frequency

Index of refraction

______ is frequency dependent

Index of refraction

At the critical angle and greater, the refracted ray ______ and all the light is ______ or _______

disappears, reflected, total internal reflection

The critical angle is the rationale behind _____

Fiber optic communications (all the energy of the data stays inside the fiber)

Diamonds sparkle with more light because of ______.

Total internal reflection

When the speed in the new medium is faster in refraction, the wave goes through a ______.

180º phase change

When the speed in the new medium is slower, the wave does not change its ______.

phase

Fixed end

wave goes upside down and other direction after phase change

Free end

wave changes direction after phase change

During refraction, the transmitted, or refracted wave _____ undergoes a phase change.

NEVER

Mirrors can be

planes, convex, concave

Lenses are either

convex, concave

Mirrors use the law of ______ because they______.

Reflection, reflect light

Lenses use law of ______ because they ______.

Refraction, transmit light

Ray diagrams represent _____.

What a specific lens or mirror does to an image.

Three easy rays to draw include _____.

Parallel -> focal point

Focal point -> parallel

Center

Focal point

The point at which rays or waves meet after reflection or refraction, or the point from which diverging rays or waves appear to proceed

F (focal point) has a negative value when _____.

It's on the opposite side of the lens than the object

Upright

Image same side (of principal axis) as object

Inverted

Image opposite side (of principal axis) as object

Magnified

Image height (absolute value) is greater than object

Diminished

Image height of image less than object

Same height

Image height = object height

Real

Can be projected onto a screen. Mirrors: same side as object, lenses: opposite side

Virtual

Does not project on a screen. Mirrors: opposite side, lenses: same side

How to draw ray diagrams

focal points and parallels basically

If objects are past the second focal length

The image is usually smaller

If objects are between the first and second focal lengths

The image is usually larger

If objects are less than one focal length

Usually larger, can be weird

If objects are at the second focal length

Pretty much the same

Thin lens equation

1/f = 1/di + 1/do

f

focal distance of the lens

di

distance of the image

do

distance to the object

f is positive for _____ and _____.

converging -> convex lenses, concave mirrors aka positive when the focal point and yo eyeballlll on the same side

f is negative for _____ and _____.

diverging -> concave lenses, convex mirrors

Magnification Equation Definition

Determines how much the image is magnified or diminished

Magnification Equation Formula

M = -(di/do) = (hi/ho)

d = distance

h = height

sin(critical angle)

n2/n1