Optics

Question 1

Why is sunlight important to the Earth?

Answer 1

It heats the Earth’s surface which allows photosynthesis to occur

Question 2

What do scientists call the “small packets of light energy”?

Answer 2

Photons

Question 3

What are the 4 properties of light?

Answer 3

1) Light travels at a high speed
2) Light travels in straight lines
3) Light is a form of energy
4) Light travels in a vacuum

Question 4

What is a thin beam of light called?

Answer 4

A light ray

Question 5

What is a light ray represented by?

Answer 5

An arrow

Question 6

Medium

Answer 6

Any substance through which energy can be transferred

Question 7

Radiation

Answer 7

A method of energy transfer that doesn’t require a medium; The energy travels at the speed of light

Question 8

Electromagnetic Waves

Answer 8

A wave that has both electric and magnetic parts and travels at the speed of light

Question 9

Visible Light

Answer 9

Electromagnetic waves that the human eye can detect

Question 10

Electromagnetic Spectrum

Answer 10

A scale of electromagnetic waves

Question 11

What are the 7 types of electromagnetic waves from largest to smallest?

Answer 11

1) Radio Waves
2) Microwaves
3) Infrared Light
4) Visible Light
5) Ultraviolet Light
6) X-rays
7) Gamma Rays

Question 12

What is one use for every type of electromagnetic wave?

Answer 12

Radio Waves: AM/FM Radio

Microwaves: Microwave Ovens

Infrared Light: Remote Controls

Visible Light: Rainbows

Ultraviolet Light: Kills Bacteria in Food and Water

X-rays: Medical Imaging

Gamma Rays: Cancer Treatment

Question 13

Light

Answer 13

A wave of energy that can be natural or artificial. It has different wave lengths, all with different colours

Question 14

Luminous

Answer 14

Objects that emit their own light

Example: The sun

Question 15

Non- Luminous

Answer 15

Objects that don’t emit their own light Example: The moon

Question 16

Light From Incandescence

Answer 16

The process of emitting light because of a high temperature

Example: Light Bulb

Question 17

Light From Electrical Discharge

Answer 17

The process of emitting light because of electricity that passes through a gas

Example: Neon Signs

Question 18

Light From Phosphorescence

Answer 18

An object that can emit light for a period of time after light has been shined on it

Example: Glow in the dark toys

Question 19

Light From Fluorescence

Answer 19

The process of emitting light while receiving energy from a different source

Example: Fluorescent light bulbs

Question 20

Light From Chemiluminescence

Answer 20

The process of changing chemical energy into light energy with little change in temperature Example: Glow Sticks

Question 21

Light From Bioluminescence

Answer 21

A chemical reaction that takes place inside a living organism that makes them emit light

Example: Bacteria

Question 22

Light From Triboluminescence

Answer 22

The production of light from friction as a result of scratching, crushing or rubbing certain chemicals together

Example: Biting into a wintergreen lifesaver

Question 23

Light From LED

Answer 23

Light emitted when the diode is connected to an electoral current which excited the electrons making them release photons that we see as light

Example : Flashlight

Question 24

Object

Answer 24

The thing being studied that produces the original rays of light

Question 25

Image

Answer 25

The pattern that results from the reflected light rays

Question 26

What are the 4 characteristics to remember an image?

Answer 26

1) **S**ize 2) **A**ttitude 3) **L**ocation 4) **T**ype **SALT**

Question 27

Rectilinear Propagation

Answer 27

A property of light meaning that light travels in straight lines

Question 28

Light Ray

Answer 28

The pathway taken by light

Question 29

Light Beam

Answer 29

A bundle of light rays

Question 30

Converging Beam

Answer 30

A beam of light in which the light rays focus to a point

Question 31

Diverging Beam

Answer 31

A beam of light in which the light rays spread out from a point

Question 32

Regular Reflection

Answer 32

The reflection of light off a smooth, shiny surface

Question 33

Incident Ray

Answer 33

A ray of light travelling from a source towards an object

Question 34

Reflected Ray

Answer 34

A ray of light that reflects off the surface of an object

Question 35

The Point Of Incidence

Answer 35

The point where the incident ray strikes the surface of the object

Question 36

Normal

Answer 36

The line drawn from the surface at an angle os 90 degrees to the reflecting surface (Shown with a dotted line)

Question 37

Angle Of Incidence

Answer 37

The angle between the incident ray and the normal

Question 38

Angle of Reflection

Answer 38

The angle between the reflected ray and the normal

Question 39

Mirror

Answer 39

Any polished surface reflecting an image

Question 40

Reflection

Answer 40

The bouncing back of the light from the surface

Question 41

What are the 2 parts of a mirror? What are they made out of?

Answer 41

1) Front Part: A sheet of glass 2) Back Part: A thin layer of reflective silver of aluminum

Question 42

What are the 2 laws of reflection?

Answer 42

1) The angle of the *Incident Ray *is equal to the angle of the *Reflected Ray* 2) The incident ray, the reflected ray and the normal all lie in the same plane

Question 43

Specular Reflection

Answer 43

Reflection of light off of a smooth surface Example: Still Water

Question 44

Diffuse Reflection

Answer 44

The reflection of light off an irregular or dull surface Example: Disco Ball

Question 45

When bouncing a ray off of 2 mirrors, what conclusion can u make about the incident ray and reflected ray? \*Review "The Laws of Reflection" Lab"

Answer 45

The orginal incident ray is alwaus parallel to the reflected ray from the second mirror

Question 46

What is the connection between *Dyslexia *and reflection?

Answer 46

People with Dyslexia have diffuculty reading off of white paper because light reflects off of it

Question 47

What do people with Dyslexia wear to avoid reflection?

Answer 47

Glasses or coloured filters

Question 48

Concave Mirror

Answer 48

A mirror shaped like a spere; inner surface is reflective

Question 49

Convex Mirror

Answer 49

Mirror shaped like a sphere: outter surface is reflective

Question 50

Centre of Curvature

Answer 50

The centre of the sphere like mirror

Question 51

Principal Axis

Answer 51

The line through the centre of the curvature to the midpoint of the mirror

Question 52

Vertex

Answer 52

The point where the principal axis meets the mirror

Question 53

Focus

Answer 53

The point at which light rays parallel to the principal axis converge when they are reflected off a concave mirror

Question 54

What are the 4 *Imaging Rules** For Concave Mirrors*?

Answer 54

1) A light ray is parallel to the principal axis is reflected through the focus 2) A light ray through the centre of curvature is reflected back onto itself 3) A ray through f will reflect paralled to the principal axis 4) A ray aimed at the vertex will follow the law of reflection (Incident Ray=Relfected Ray) \*1 AND 3 TRAVEL IN OPPOSITE DIRECTIONS\*

Question 55

What are the 3 *Imaging Rules for Convex Mirrors*?

Question 56

What does a convex mirror always produce?

Answer 56

A virtual image

Question 57

To determine if an image is in a plane mirror what is needed?

Answer 57

a minimum of 2 rays

Question 58

If the rays are extened behind a mirror what does this make them?

Answer 58

Virtual

Question 59

Which way do convex mirrors curve?

Answer 59

To the left

Question 60

Which way do concave mirrors curve?

Answer 60

To the right

Question 61

An image in a plane mirror is always what?

Answer 61

Virtual

Question 62

Transparent Material

Answer 62

Light easily passes through the material and a clear image can be seen through the material

Question 63

Translucent Material

Answer 63

Light passes through the material but is scattered and no clear image can be seen

Question 64

Opaque Material

Answer 64

No light passes through the material. All light energy is absorbed or reflected.