Grade 10 optics

bioluminescence is a form of

chemiluminescence

a mirror is a mirror is also called a converging mirror

concave

a convex mirror always produces a _

VIRTUAL image

microwaves have a longer wave length and _. than visible light

lower energy

the only form of electromagnetic radiation that can be detected by the human eye is

visible light

when an object is heated to a point that it glow, the process is called

incandescence

_ involves passing electricity through a gas, casing the gas to glow

electric discharge

phosphorescent light sources absorb uv light and emit visible light _

slowly

some products prevent sunburn by blocking light from the sun

UV

__ percent of the electric energy that passes through an incandescent light bulb is converted to light energy

less than 10 percent

in order for a spotlight with a curved mirror to work properly, a bright light source must be placed at the __ of a mirror

focus

compact florescent light bulbs are much more _

efficient than incandescent

_- reflection occurs when light rays strike a dull surface

diffuse

if you don't have a protracter, you can locate a image in a plane mirror by using

equal perpendicular lines

if you hold a shaving mirror close to your face, the image you see in the mirror will be because your face is closer than F

enlarged

if oxygen is present, running an electric current through a__- wire will make the ware so hot that it catches fire

tungsten

light always travels ___

in a straight line

when you use a remote to control the tv, the remote is emitting

infrared radiation

a ray of red light has a frequency than a ray of yellow light

lower

fluorescence occurs when an object absorbs . and immediately releases the energy as visible light

UV light

incandescence is a process by which an object gives off light because it is

hot

fire flys make light by combining __-

luciferin, oxygen and luciferaise

A farmer who wants to provide a small source of heat for its chickens should use

incandescence light bulbs

as an object moves closer to a concave mirror, its reflection will vanish for a moment nd this will tell you _

where the mirrors focus is!

how is an image in a plane mirror different than an image in a converging mirror?

plane mirror=virtual (it appears behind the mirror but no light actually comes fro an apparent location of the image to your eyes

converging=real (if you held up a screen, the image would appear on the screen)

how would you explain how to find a virtual image of an object in a plane mirror using a diagram

I would draw a series of object-to-mirror lines on the left side of the mirror that were perpendicular to the mirror. on the right side of the mirror, I would draw image-to-mirror lines that were congruent to the lines above. then I would use the lines to draw the virtual image.

how would you summerize the imaging rules of a converging mirror

-a light ray that is parallel to the PA will reflect through F

-Alight ray that passes through F will reflect along a line that is parallel to the PA

-A light ray that strikes V will follow the law of reflection in which the incident angle is congruent to the reflection angle

-A light ray aimed at 90 degrees at the centre of the mirror will reflect back on itself

what is the difference between a real and a virtual image

a real image is formed when light rays actually converge which means it can be formed on a paper screen placed at the location

A virtual image is formed when light rays appear to be behind the mirror which means that they cant be formed on a paper screen

What does SALT stand for

Size, Attitude, Location, Type

Why does SALT help you describe the properties of an image

they precisely help you identify what and where the image is

when a path of light enters a pond, its path bends

toward the normal

If the index of refraction of water is 1.33, then the speed of light in water is equal to the speed of light in a divided by 1.33

vacuum

when a light beam travels from a solid to a vacuum, the angle of incidence is ____ then the angle of refection

greater

You look down at an aquarium and see a fish. the fish appears to be 75 cm below the surface of the water. therefore, you know that the fish is actually __- below the surface

more than 75cm

Light travels through a fiber optic cable because the incident angle of the light is than the critical angle of the material that makes up the fibre

larger

When you look down in a lake and see a rock, you are seeing a __ image

virtual

___ occurs when light passes through a prism , creating a rainbow of colours

dispersion

A total internal reflection occurs _ times in a diamond than it does in a triangular prism

more

A shows a good example of total internal reflection

diamond

The difference between the speed of light and in a vacuum and the speed of light in ___ is very small

air

The angle of refraction is the angle between __ and the normal

the refracted light ray

the refracted ray the _ and the normal all lye on the same plane

incident ray

the change in the ___ of a light ray at the boundary of a substance causes refraction

speed

The _ of refraction of the medium is the ratio of speed to light in a vacuum to the speed of light in that medium

index

What is the formula for the index of refraction

n = c/v

When light _ at the boundary of 2 media, the angle of refraction is always larger than the angle of incidence

speeds up

When light slows down at the boundry of 2 media, the angle of refraction is always ___ than the angle of incidence

smaller

When the angle of refract _- to 90, the angle of incidence is the critical angle

equal

When the light ray enters a medium at an angle greater than the critical angle of the medium, the refracted ray does not ___

exit the medium

When an incident ray is reflected by a transparent medium, you know that the angle of incidence was greater than the angle of - of the medium

critical angle

When refraction occurs, the __-- and the refracted rays are on opposite sides of the boarder between the 2 media

incident ray

In order for refraction to occur, 2 media must have ___ index of refraction

a different

When you calculate an index of refraction, the values your calculations will have __

the same units

The critical angle is the anglE of incidence that produces a _ of 90

refracted angle

Prisms rather than mirrors are used in optical devices because over long periods of time, miRrors require

maintenance

Prisms reflect _ of an incident light than mirrors do

more

A pencil in a glass will appear +___ if you look at it from the side of the glass

bent

what a beam of light _ a body of water, its path is bent away from the normal

exits

When a beam of light travels from a diamond into the air, the angle of refraction is ___ than the angle of incidence

greater

the index of refraction of glass is 1.52 and of acrylic is 1.49. this tells you that _- of acrylic is is greater than that of glass

critical

The angle of refraction is the angle formed by the refracted light ray and the

normal

Refracted light follows the same path even you switch its original direction. this is called the principal of

the reversibility of light

sin i/sin r is equal to

n (the refractive index) = c/v

Refraction is caused by

light changing speed as it enters a new medium

glass has a greater index of refraction than vegetable oil, so light moving from a glass medium to a veg oil medium will bend __ the normal

away from

A mediums index of refraction equals the speed of light in __ decided by the speed of light in that medium

a vacuum

how can a window both be reflective and transparent

When light strikes a windows glass, some of it is reflected back to our eyes which shows us a reflection of what's behind it. But some light passes through the window, illumination whatever is behind it

Compare and contrast what happens when a light ray traveling through a pond strikes the surface at an less than critical angle

the light ray will emerge from the pond water bent away from the normal, closer to the surface of the pond

Compare and contrast what happens when a light ray traveling through a pond strikes the surface at an equal to the critical angle

the light ray will be refracted along the surface of he pond.

Compare and contrast what happens when a light ray traveling through a pond strikes the surface at a greater then the critical angle of water

the light ray will be reflected back down into the water

what type of image does a magnifying glass form?

an enlarged, upright, virtual image

A terrestrial telescope differs from an astronomical telescope because of its ___

number of lenses

In a human eye, what is the retna compared to?

the digital sensor on a camera

What condition causes farsightedness

presbyopia

When you focus a camera

you are changing the position of the lense

if you are looking through a microscope and move the slide to the right, it will appear to

have moved left

if both faces of a lense are convex, what is the lense called?

converging lense

If both faces of a lense are concave, it is a __

diverging lense

what lense can you use to start a fire on a sunny day?

a converging lense

why is a positive meniscus lense named the way it is?

its called positive because it is thicker in the middle than it is on the edges

A negative meniscus is

a lense thta is thinner in the middle than it is in the edges

What takes light from large distant objects And forms an image that is small, real and inverted

camera

what takes a small object and makes a large, real inverted image

a projector

how many lenses and what type does a compound microscope have?

2,, converging

what part of a camera is the same as the iris

diaphragm

what is the process of changing the focal length of the lens. in the eye called

Accomidation

In the eye of a person with myopia, where I light from some objects focused

in front of the retna

Your friend is trying to look at a tiny diagram using a magnifying glass. he is holding the glass about 40cm above the page but keeps bringing his eye closer and closer to the lense but still can't see the diagram clearly! what is he doing wrong?

He is holding the magnifying glass to far from the page. In order for a magnifying glass to focus, the object must be less than the focal length away from he lense

You're holding an object in front of the converging lense at a distance greater than 2F. The image is real, inverted smaller than the object and located between F and 2F. Describe what happens to the image as the object is moved closer ad closer.

As the object gets closer, the image gets larger and moves away from the lense. When the object reaches 2F, the image is at 2f and is the same size as the object. it continues to get larger and move away from the lense until the object reaches F which is where it disappears. Once the image moves past F, an image appears that is virtual, upright, larger than the object and on the same side of the lense

What are the similarities and differences between a film camera and a human eye

Both have parts that open and close to control the amount of light that enters (camera=diaphragm, eye=pupil). Camera has lense, eye has cornea and lense and both form a smaller, inverted, real image on a back surface! On a camera, an image forms on a film while with eyes, it forms on your retna. The eye has an optic nerve to carry signals from retna to brain while cameras have no analogous part. Eye is living tissue wile a camera is a manufactured machine

What are the differences and similarities between a compound microscope and A refracting telascope

Both have objective lenses on one end and eyepieces on the other

Both, objective lenses create enlarged, real, inverted imGES INSIDE THE BODY of the instrument

In both, the eyepiece takes the real image and uses it to form an enlarged, virtual, re-invented imAge that you see

Difference: telescope: used to see things so far away that the light rays from them are essentially paralell.