Science Optics Unit: Complete Review

Front 1

List the electromagnetic waves in order from lowest energy to highest energy: green light, microwaves, x-rays, ultraviolet light, infrared light, red light, radio waves

Back 1

radio
microwave
infrared
red light
green light
radio waves

* wavelength increases as energy increases (gamma rays have the largest)

Front 2

Order the colours of the rainbow from shortest wavelength to longest wavelength:

Back 2

Red, orange, yellow, green, blue, violet

Front 3

True or False: In order to see an object, light must be reflected from that object into your eyes.

Back 3

True

Front 4

List that seven colours that Newton identified in the visible spectrum of white light.

Back 4

Red, orange, yellow, green, blue, indigo, violet

Front 5

What is the relationship between frequency and wavelength of a wave?

Back 5

Inverse

As the frequency increases, the wavelength decreases.
As the frequency decreases, the wavelength increases.

Front 6

What colours are absorbed in a green object? What colours are reflected?

Back 6

White light is absorbed.
Green light is reflected.

Front 7

What colours are absorbed in a white object? What colours are reflected?

Back 7

White light is absorbed.
All colours are reflected.

Front 8

What colours are absorbed in a black object? What colours are reflected?

Back 8

White light is absorbed.
No colour is reflected.

Front 9

Why is an incandescent light an inefficient light source?

Back 9

An incandescent light gets hot and glows brightly when current flows through.
Incandescence is light emitted from very hot objects.
5% efficient at producing light & 95% lost as heat.
95% efficient at producing heat & 5% lost as light.

Front 10

What is the main difference between phosphorescence and fluorescence?

Back 10

Fluorescent material absorbs light of one wavelength and emits light of another wavelength.
Phosphorescent materials are charged my exposure to UV light. These materials release the energy slowly over time.

Front 11

What has historically been the main use of plane mirrors?

Back 11

To see your reflection.

Front 12

What would the angle of incidence been for an angle of reflection of 47 degrees?

Back 12

Angle of incidence = angle of reflection
(Therefore the angle of incidence would be 47 degrees to the normal)

Front 13

How would the word ECNALUBMA appear when viewed in a plane mirror?

Back 13

Ambulance

Front 14

Some restaurants cover an entire wall with a large, plane mirror. What effect does this have on the appearance of the restaurant? Why does this happen?

Back 14

-A large mirror makes a room look larger because it creates an illusion of depth
-It tricks the eye into thinking there is more space than there really is.
- The optical illusion occurs as the mirror reflects light and colour across the room.
- A large mirror has more surface area to allow for more angles of incidence.
- With more angles of incidence, there will be more angles of reflection.
- Our eyes perceive the bouncing reflections as increase volume, making the room look bigger.

Front 15

What are the two rules of reflection for a plane mirror?

Back 15

Angle of incidence = angle of reflection
Distance of the object in front of the mirror = distance of the image behind the mirror

Front 16

Where must an object be located in order for a concave mirror to form:
a) a real image
b) a virtual image

Back 16

a) anywhere outside of the focal point
b) between the focal point and the mirror

Front 17

Why will a convex mirror NEVER form a real image?

Back 17

- Rays will never cross in front of the mirror
- Rather the rays will appear to spread out from a point behind the mirror.
- Therefore creating a virtual focal point or virtual image.

Front 18

What are the three rules of reflection for a curved mirror?

Back 18

1. Rays that travel parallel to the principal axis will always reflect through the focal point.
2. Rays that travel through the focal point will always reflect parallel to the principal axis.
3. Rays that pass through the center of curvature will always reflect back on itself.

Front 19

What type of mirror produces diverging rays?

Back 19

Diverge means to spread out.
A convex mirror causes light rays to spread out (diverge).

Front 20

What type of mirror can produce converging and diverging rays?

Back 20

A concave mirror can produce both converging and diverging rays depending on where he object is placed.
1. When the object is between the focal point and the mirror: diverging rays
2. When object is outside of the focal point: converging rays

Front 21

Light bends towards the normal when going from material A into material B. Compare the speed of light in the two materials.

Back 21

Speed of light in material A= Faster
Speed of light in material B= Slower

Front 22

What TWO conditions must be satisfied for total internal reflection to occur?

Back 22

1) Light must be traveling from a slow medium to a fast medium.
2) Angle of incidence must be greater than the critical angle.

Front 23

A certain substance has a critical angle of 24.5. What minimum angle of incidence, to the nearest tenth of a degree, will result in total INTERNAL reflection?

Back 23

Total internal reflection will take place at 24.6 degrees.

Front 24

A bean of light is traveling from air to glass. Would refraction still occur if light travelled at the same speed in both air AND glass? Explain.

Back 24

No, because the speed of light is the same in both materials.
Refraction occurs when the speed of light changes due to the different optical densities of the materials.

Front 25

What are the three rules of refraction for any lens?

Back 25

1. When a light ray travels parallel to the principal axis, it will always refract through the primary focus.
2. When a light ray travels through the secondary focus it will refract parallel to the principal axis.
3. When light rays travel diagonally through the center of the lens, it will continue straight through without refracting.

Front 26

Compare the pupil to a doughnut hole. In this analogy, what structure in the eye represents the doughnut? How does this structure work?

Back 26

- The iris would represent the doughnut. The iris is your eye colour.
- The iris regulates the amount of light that enters the lens of the eye.
- If a room is really bright, the iris constricts (becomes smaller) to minimize the amount of light entering the lens. The pupil (black hole at the center of the eye) will appear smaller.
- If a room is dark, the iris dilates (becomes larger) to maximize the amount of light entering the lens. The pupil will appear larger.
-ALSO IF HAYLEY SEES CONNOR BAIGRIE HER PUPILS WILL DILATE

Front 27

What is the shape of your lens when viewing distant objects? What is the shape of your lens when viewing nearby objects?

Back 27

- Distant objects: Lens flatter. (ciliary muscles relax)
- Near objects: Lens thicker. (ciliary muscles contract)

Front 28

What type of lens should a person who is far sighted use? Nearsighted?

Back 28

Farsighted: Convex
Nearsighted: Concave