Physics - Optics

Question 1

What is light?

Answer 1

A stream of photons that are massless particles each travelling with wavelike properties at the speed of light (it can travel without a medium). A photon is the smallest quantity of energy which can be transported

Question 2

What makes an object Luminous?

Answer 2

Objects that are able to emit their own visible light (eg. light bulbs, the sun and other stars, matches)

Question 3

What makes an object Non-Luminous?

Answer 3

Not capable of producing light, but can be capable of reflecting light from another source (eg. wood, plastics, the moon)

Question 4

What does Incandescence mean?

Answer 4

emits light as a result of being heated (eg. Candle, fire, stove burner, light bulb)

Question 5

What does Electrical Discharge mean?

Answer 5

An electric current passes through gas and causes it to glow (eg. Flashlights, neon lights, lightning)

Question 6

What does Phosphorescence mean?

Answer 6

Emission of light from a substance-exposed to radiation object absorbs UV light and emits visible light in the eye

Question 7

What does Fluorescence mean?

Answer 7

Absorbs UV light and emits visible but through the use of gases and chemical discharge (eg. Detergent, fluorescent light bulbs)

Question 8

What does Bioluminescence mean?

Answer 8

Light is emitted by a living organism, this is a type of chemiluminescence. The light is produced from a chemical reaction (eg. Fireflies, glow worms, jellyfish, angler fish)

Question 9

What does Triboluminescence mean?

Answer 9

The light produced by friction or contact between crystals

Question 10

What does Light-Emitting-Diode (LED) mean?

Answer 10

Only allow energy to flow in one direction with the use of semiconductors. They produce very little heat when they emit light (eg. Christmas lights, cars, screens, flashlights)

Question 11

What is the Electromagnetic Spectrum

Answer 11

The electromagnetic spectrum is the range of frequencies of electromagnetic radiation and their respective wavelengths and photon energies.

Question 12

What is the relationship between wavelength and energy?

Answer 12

the shorter the wavelength, the higher the energy* (gamma rays have the highest energy, radio waves have the lowest

Question 13

What are the seven radiation types (in order from the shortest wavelength to the longest wavelength?

Answer 13

• Radio
• Microwave
• Infrared
• Visible
• Ultraviolet
• X-Ray
• Gamma Ray

Question 14

What is the speed of light?

Answer 14

The speed of light is c = 3 x 10^8 m/s

Question 15

whats an example of radio waves

Answer 15

television

Question 16

what an example of microwave waves

Answer 16

microwaves

Question 17

whats an example of infrared waves

Answer 17

burning charcoal

Question 18

whats an example of visible waves

Answer 18

the sun

Question 19

whats an example of ultraviolet waves

Answer 19

nail thingy like the things they have in nail salons to cure the manicure

Question 20

whats an example of xray waves

Answer 20

xrays, scanning for fractures, etc

Question 21

what an example of gamma ray waves

Answer 21

cancers treatment

Question 22

what are the similarities between radiation types

Answer 22

• All are types of electromagnetic waves (energy transfer)

- Travel at the same speed

Question 23

what are the differences between radiation types

Answer 23

• Wavelength (waves from 1 peak to another) - Longer wavelength = less energy
• Energy level (placed different on the spectrum)
• only one type of wave is visible to our naked eyes - VISIBLE LIGHT

Question 24

what is the law of reflection

Answer 24

Angle of incidence (oi) = angle of reflection (or)

Question 25

if the object was beyond c in a concave mirror, what is salt

Answer 25

smaller inverted between f and c real

Question 26

if the object is at c in a concave mirror what is salt

Answer 26

same inverted at c (it should be identical to the top) real

Question 27

if the object is between f and c in a concave mirror what is salt

Answer 27

larger inverted beyond c real

Question 28

if the object is at f in a concave mirror what is salt

Answer 28

there is no image formed

Question 29

if the object is between f and v in a concave mirror what is salt

Answer 29

larger upright behind mirror virtual

Question 30

if the object is far beyound c in a concave mirror what is salt

Answer 30

smaller inverted between f and c real

Question 31

(concave) Any incident ray parallel to the PA will

Answer 31

reflect through F

Question 32

(concave) Any incident ray passing through F will

Answer 32

reflect parallel to the PA

Question 33

(concave) Any incident ray striking the vertex will

Answer 33

reflect at the same angle

Question 34

(concave) Any incident ray passing through C will

Answer 34

bounce back through C

Question 35

(convex) Any incident ray parallel to PA will

Answer 35

reflect as if it were to pass through the focal point

Question 36

(convex) Any incident ray moving towards F, will

Answer 36

reflect parallel to the PA

Question 37

(convex) Any incident ray moving towards C will

Answer 37

reflect back upon itself

Question 38

(convex) Any incident ray striking v will

Answer 38

reflect back at the same angle (oi=or)

Question 39

what is salt for a convex mirror

Answer 39

smaller upright behind mirror virtual

Question 40

what is refraction

Answer 40

The change in direction or speed of light when it travels from one medium into another.

Question 41

what happens when light travels from a faster medium to a slower one

Answer 41

the light bends towards normal

Question 42

whats a real life application of refraction

Answer 42

a rainbow, the light refracts through the raindrops

Question 43

what is apparent depth

Answer 43

Since the light rays travelling from the object to our eyes bend away from the normal when they travel from water to air, the refracted rays appear to be coming from a point above where the object actually is.

Question 44

what are the steps to draw a diagram for apparent depth

Answer 44

1. First draw the virtual image that will be formed higher up than the object 2. Draw the refracted rays starting from the image (dotted lines) to the observer in a straight line. Make sure the actual refracted rays are bolded lines. 3. Draw the normal where the refracted rays change mediums. 4. Connect the refracted rays to the point on the object they originate from.

Question 45

what does each variable in the index of refraction equation stand for

Answer 45

``` N = index of refraction C = velocity of light in a vacuum (speed of light) V = velocity of light in the medium ```

Question 46

what are the two conditions for total internal reflection to occur

Answer 46

- the angle of incidence is greater than the critical angle and therefore totally reflects light (no refraction occurs) - medium one has to be more optically dense than medium 2

Question 47

what is an application of total internal reflection

Answer 47

Diamonds - they cut the diamond in a way that traps the light inside of it and reflects out the top making it sparkle

Question 48

what are some applications of a convex mirror

Answer 48

security camera, side car mirrors, hallway mirrors (they show a wider view)

Question 49

what are some applications of a concave mirror

Answer 49

makeup mirrors, bathroom mirrors, spotlights (they focus on a small area)

Question 50

what is hyperopia

Answer 50

Farsightedness Light focuses behind the retina To correct → converging lens

Question 51

what is myopia

Answer 51

Nearsightedness Light focuses before the retina To correct→ diverging lens