Light and Optical Systems

Question 1

name the 2 types of light

Answer 1

natural (sun, fire, bioluminescent)

artificial (LED, fluorescent, incandescent, phosphorescenct, chemiluminescent

Question 2

ray model of light

Answer 2

(an explanation based on observation of how light behaves)

light travels in straight lines

a “ray” is a straight line that represents the path of a beam of light

Question 3

law of reflection

Answer 3

the angle of incident is the same as the angle of reflection and same with the incident ray and reflection ray

angle of incidence = angle of reflection

Question 4

Two characteristics that make telescopes useful for observing the skies are their ability to:

a) separate and magnify light
b) magnify and collect light
c) collect and separate light
d) magnify and clarify light

Answer 4

b) magnify and collect light

Question 5

The difference between a convex lens and a concave lens is:

a) convex lenses are thicker in the middle
b) concave lenses are thicker in the middle
c) convex lenses spread out light rays
d) concave lenses concentrate the light

Answer 5

a) convex lenses are thicker in the middle

Question 6

plane mirror

Answer 6

reflection

same size, same distance, virtual image

Question 7

A plane mirror has a(n):

a) curved surface
b) focal point
c) ability to bend light
d) flat surface

Answer 7

d) flat surface

Question 8

A concave mirror reflects rays so that they:

a) converge to focal point
b) diverge and spread out
c) reflect and converge to a focal point
d) reflect and diverge or spread out

Answer 8

c) reflect and converge to a focal point

Question 9

name the 5 sources of light

Answer 9

fluorescent

incandescent

phosphorescent

chemiluminescent

bioluminescent

Question 10

fluorescent light?

Answer 10

UV radiation

coating glows and produces light

more expensive and difficult to dispose of

phosphor coating and mercury vapor are toxic

ultraviolet light energy –> energy absorbed by particles –> visible light energy

Question 11

incandescent light?

Answer 11

So hot it glows

(candle, light bulb)

electrical energy –> thermal energy –> visible light energy

Question 12

phosphorescent light?

Answer 12

radiation

(inner surface of TV and computer screens)

Question 13

chemiluminescent light?

Answer 13

chemical reactions

(glow sticks)

chemical energy –> visible light energy

Question 14

bioluminescent light?

Answer 14

chemical reactions within animal bodies

(fungi, fireflies, fish)

Question 15

LED

Answer 15

Light Emitting Diode

Electricity

very efficient

long lasting

expensive

Question 16

Name 3 types of materials

Answer 16

Transparent - light passes through (air, water)

Translucent - some rays bounce back and some go through (paper)

Opaque - materials that totally block the light and cast shadows (books, desk)

Question 17

luminous

Answer 17

produces (or emits) light

Question 18

convex mirrors

Answer 18

convex: (lens curves outward)

small / far away

reflects rays so that they reflect and diverge or spread out

car mirror/securit

Question 19

concave mirrors

Answer 19

concave: (lens curves inward)

big or upside down

(makeup mirror)

Question 20

THE EYE: ciliary muscle

Answer 20

changes shape to focus

Question 21

THE EYE: lens

Answer 21

focuses light

the more CONVEX (fat) the lens is, the more rays are refracted

Question 22

THE EYE: iris

Answer 22

the coloured part

controls the amount of light

Question 23

THE EYE: pupil

Answer 23

opening for light

Question 24

THE EYE: cornea

Answer 24

helps focus

the transparent front part of the eye that covers the
iris, pupil, and anterior chamber

Question 25

THE EYE: optic nerve

Answer 25

sends message to the brain

Question 26

THE EYE: Sclera

Answer 26

protective outer layer the white part

Question 27

THE EYE: blind spot

Answer 27

the point where the optic nerve enters the retina has no light-sensing cells

Question 28

THE EYE: vitreous humour

Answer 28

keeps shape of eye, clear

Question 29

THE EYE: aqueous humour

Answer 29

holds shape of front of eye

Question 30

THE EYE: retina (including rods and cones)

Answer 30

light sensitive cells capture image

Question 31

THE EYE: near-sighted what type of lens corrects this?

Answer 31

the image falls short of the retina vision corrected with concave lens | (eye has longer shape than normal eye)

Question 32

THE EYE: far sighted what type of lens corrects this?

Answer 32

the image falls behind the retina vision corrected with convex lens | (eye has shorter shape than normal eye)

Question 33

gamma rays

Answer 33

shortest wave length and highest frequency waves (nuclear, radiation, cancer treatment)

Question 34

x-rays

Answer 34

short wave length and capable of penetrating solids (electromagnetic radiation)

Question 35

ultra-violet (UV) radiation

Answer 35

wavelengths of 200 nm beyond violet light in the electromagnetic spectrum causes tanning nm = nanometer

Question 36

visible light

Answer 36

wave length we can see light we can see

Question 37

infra-red

Answer 37

heat radiation anything that is warmer than its surroundings emits infra-red rays longer wave-length than visible

Question 38

microwaves

Answer 38

longer wave-length than infrared | (microwaves, radar)

Question 39

THE EYE: wavelength

Answer 39

distance from crest to crest or trough to trough

Question 40

electromagnetic spectrum

Answer 40

Radio waves Microwaves Infrared waves Visible light Ultraviolet rays X-rays Gamma rays

Question 41

frequency

Answer 41

number of waves that pass a point in one second high frequency = short wavelength low frequency = long wavelength

Question 42

amplitude

Answer 42

height of the wave

Question 43

EMR: electromagnetic radiation

Answer 43

visible light energy radiant energy

Question 44

refracting telescope

Answer 44

a telescope having a **convex lens** to **collect and focus light** from a distant object and an eyepiece lens to magnify the image

Question 45

reflecting telescope

Answer 45

a telescope having a **concave mirror** to collect rays of light from a distanct object

Question 46

prisms in binoculars

Answer 46

.

Question 47

remote sensing technology

Answer 47

getting information about an object without making physical contact (such as the Hubble Space Telescope)

Question 48

when looking at a fish tank you notice that your goldfish is not where it appears to be the apparent position of the fish is due to the fact that, as light travels from the water to the air, it bends:

Answer 48

AWAY from the normal