Unit C Final Review

Question 1

4 basic properties of light

Answer 1

light travels in straight lines
light can be reflected
light can bend
light is a form of energy

Question 2

Define each of the following:
Optical device
Microscope
Refracting Telescope
Reflecting Telescope
Binoculars

Answer 2

Optical device: any device that uses light; for example, mirrors, lenses, microscopes, and telescopes
Microscope: an optical device used for viewing very small objects; has at least two lenses: the objective lens and the eyepiece lens
Refracting Telescope: a telescope that uses two lenses to form an enlarged image
Reflecting Telescope: a telescope that uses a curved mirror and a lens to form an enlarged image
Binoculars: a device for viewing distant objects; made up of two short refracting telescopes fitted together

Question 3

What happens when you pass white light through a prism?

Answer 3

The white light is separated into its component colours - red, orange, yellow, green, blue and violet.

Question 4

Describe each of the following and provide an example:
Transparent:
Translucent:
Opaque:

Answer 4

Transparent: describes materials that allow light to pass through with little or no reflection; for example, glass
Translucent: describes materials that allow some light to pass through; for example, wax paper
Opaque: describes materials that do not allow light to pass through; for example, wood, metal, cardboard, etc.

Question 5

What does the word “luminous” mean?

Answer 5

describes objects that produce light; for example, the sun, light bulb, fire, etc.

Question 6

What is the “Law of Reflection?”

Answer 6

the angle of incidence of a wave hitting a surface equals the angle of reflection

Question 7

Define each of the following:
Incident Ray:
Reflected Ray:
Refracted Ray:

Answer 7

Incident Ray: the ray of light that arrives at a mirror or other substance
Reflected Ray: the ray that leaves the mirror
Refracted Ray: The amount of bending of a light ray as it crosses a boundary between two media is dictated by the difference in the two indices of refraction.

Question 8

What is a “focal point?”

Answer 8

the point at which light rays meet, or appear to meet, after being reflected by a mirror, or refracted by a lens.

Question 9

Define each of the following:
Concave Mirror:
Convex Mirror:

Answer 9

Concave Mirror: reflecting surface that is curved inward like the inside of a bowl or spoon; light rays reflected from it converge. These rays all head to a common point called the focal point.
Convex Mirror: reflecting surfaces that bulge out like the back of a spoon; light rays reflected from it diverge (spread out).

Question 10

What type of mirror would I use when I want to see more of an image?

Answer 10

Convex mirror

Question 11

What type of mirror would I use when I want to see an image upside-down?

Answer 11

Concave mirror

Question 12

What happens to light as it passes through different mediums (ex. from air to glass). Why does this happen?

Answer 12

Refracts

Question 13

Define each of the following:
Refraction:
Concave Lens:
Convex Lens:

Answer 13

Refraction: bending of light as it travels from one material to another material. The denser the medium, the more light slows down, so the more it refracts.
Concave Lens: a piece of transparent material that is thicker in the middle than at the edges; light rays passing through it converge or come together.
Convex Lens: a piece of transparent material that is thinner in the middle than at the edges; light rays passing through it diverge or spread out.

Question 14

Wavelength:
Amplitude:
Crest:
Frequency:

Answer 14

Wavelength: distance between the top of the crest of one wave and the crest of the next.
Amplitude: Height of the wave from its middle rest position to its highest points.
Crest: highest point of a wave.
Frequency: its rate - how often it goes

Question 15

Explain how the frequency of the wave relates to its overall energy.

Answer 15

Lower frequency = lower energy. Higher frequency = higher energy

Question 16

Describe each of the following types of electromagnetic radiation and provide one example of each:
Radio Waves: 
Microwaves: 
Infrared Waves: 
Visible Light Waves: 
Ultraviolet Light Waves: 
X-Rays: 
Gamma Rays:

Answer 16

Describe each of the following types of electromagnetic radiation and provide one example of each:
Radio Waves: electromagnetic radiation used in communications around the world. least energy, low frequency, longest wavelength. ex) radios
Microwaves: electromagnetic radiation. shorter wavelength than radio waves and carries more energy. more frequent. ex) used to cook food.
Infrared Waves: electromagnetic waves that have less energy than visible light; they are invisible but can be felt as heat. ex) infrared goggles see heat patterns
Visible Light Waves: They are found from the sun and are used to see clouds and to help predict the weather. We not only look at the Earth from space but we can also look at other planets from space. more energy. ex) sunlight
Ultraviolet Light Waves: energetic rays from the sun. ex) tanning beds
X-Rays: high-energy electromagnetic radiation. ex) medical x-rays
Gamma Rays: high-energy electromagnetic radiation with the shortest wavelength. ex) cancer treatment

Question 17

Describe each of the following sources of light:
Incandescent: 
Fluorescent: 
Phosphorescent:
Bioluminescent:

Answer 17

Describe each of the following sources of light:
Incandescent: an object that can be heated to such a high temperature that it emits visible light. ex) when your stove gets red or bright red lava.
Fluorescent: bright and glowing as a result of fluorescence fluorescent inks broadly. very bright in colour. ex) LED lights
Phosphorescent: a substance that gives off visible light released after the light energy has been absorbed by certain particles that have stored this energy for a while. The light continues for some time even after the substance is no longer exposed to the light. ex) glow in the dark roof stickers
Bioluminescent: the emission of light produced by chemical reactions inside the bodies of living creatures. ex) fireflies or jellyfish

Question 18

Define each of the following:
Pupil: 
Iris: 
Cornea:  
Eye lens:
Retina: 
Optic Nerve: 
Rods:
Cones:

Answer 18

Define each of the following:
Pupil: opening in the eye that lets in the light. the black circle.
Iris: a band of muscle in the eye that controls the size of the pupil and the amount of light entering the eye. the coloured part of the eye
Cornea: The cornea is the clear outer layer at the front of the eye. helps you focus light to see clearly.
Eye lens: The eye lens has to be put into a position where the lens is relaxed enough to move so the image can be seen clearly. It is the thick/thin part behind the iris.
Retina: Special lining on the back of the eye when light hits the retina receptors cells send messages to the brain through the optic nerve which translates them into images.
Optic Nerve: the nerve that leads from the retina to the brain. sends messages of what you are seeing.
Rods: specialized cells in the retina that are sensitive to low-level lights.
Cones: specialized cells in the retina that detect colours there are three types of cones each sensitive to different colours red, green and blue.

Question 19

Define each of the following:
Aperture: 
Shutter: 
Camera Lens: 
Diaphragm: 
Film: 
Pixel: 
Resolution:
Charged-Coupled Device:

Answer 19

Aperture: hole or opening in a camera that lets in light. like eye pupil
Shutter: the part that acts as a door to control the amount of light entering a camera. like eye iris
Camera Lens: A lens is a tool used to bring light to a fixed focal point. like your eye’s cornea.
Diaphragm: change the size of the aperture in the lens to allow the proper amount of light. similar to an eye lens.
Film: When light strikes the film, the film changes chemically forming an image. similar to the retina.
Pixel: Short for picture element; the individual elements of a digital image
Resolution: the number of pixels per unit area in a digital image
Charged-Coupled Device: device that converts light into electrical energy; used in digital cameras. a grid with electricity in it.

Question 20

Explain what happens in the eye of a person with: (use a diagram in your answer)
near-sightedness:
far-sightedness:

Answer 20

near-sightedness: Can’t see distant objects clearly. The eye can not make the lens thin enough to focus on the light.
far-sightedness: Can’t see near things clearly. the eye can not make the lens fat enough and make it focus on light on the retina.

Question 21

Define each of the following:
compound eye:
camera eye:

Answer 21

compound eye: eyes that are made up of many smaller units; found in insects and crustaceans
camera eye: Eyes that have a cornea, a lens, a retina, and are roughly round in shape are called camera eyes. most animals.