Optics

Question 1

Types of light and describe them

Answer 1

Natural light eg: Sun and organisms

Artificial light: Light bulbs (Incandescent, sodium vapour, fluorescent)

Question 2

Luminescence

Answer 2

Light generated without heat. 3 types of Luminescence, Phosphorescence, Chemiluminescence, bioluminescence

Question 3

Phosphorescence

Answer 3

Type of luminescent light, light emitted for some time after ultraviolet radiation has stopped. Eg, Glow in dark paint, ceiling stars

Question 4

Chemiluminescence

Answer 4

Light generated by energy released during a chemical reaction. Eg, Glow in the dark, fireworks, match stick

Type of luminescence

Question 5

Bioluminescence

Answer 5

Light produced by living organisms. Angler fish, jellyfish, fireflies. Type of luminescence

Question 6

Fluorescence

Answer 6

Emission of light by a substance that absorbs electromagnetic radiation (eg, UV radiation). Molecules go in an excited state but do not stay in it for lose and they lose energy in the form of heat light.

Eg, Highlighter, tonic water, laundry detergent.

Question 7

Properties of waves

Answer 7

Crest - highest point of wave

Trough - Lowest point on wave

Amplitude - Wave height from rest position of the wave to crest.

Wavelength - Distance from one crest to the next crest. UNIT (M)

Question 8

Wave

Answer 8

A disturbance that transfers energy from one point to another without transferring matter

Question 9

Frequency

Answer 9

Number of wavelenghts per second (Symbol: f; units: Hz or S-1^)

Question 10

Electromagnetic spectrum

Answer 10

Light is made of energy that behaves as both a wave and a particle but does not require matter to travel

Question 11

Light

Answer 11

A complex form of energy which contains both particles (phontons) and waves

Question 12

What is electromagnetic radiation classified according to?

Answer 12

Wavelength

Question 13

What does shorter wavelengths mean

Answer 13

More energy the radiation possess

Question 14

Types of electromagnetic rays and examples

Answer 14

Radio - FM/AM radio broadcasts

Microwaves- Radar, satellite, spacecraft communication, wireless networks, cell phones

Infrared - Sunlight, fires

Visible - Red, orange, yellow, green, blue, violet

Ultraviolet - Tanning beds, used to clean water

X-ray - Medical x-rays and security x-rays

Gamma - Radiotherapy (medical), disinfection, nuclear

Question 15

Images in a plane mirror

Answer 15

Normal, Incident ray, Reflected ray, point of incidence, angle of incidence, angle of reflection

Question 16

Normal

Answer 16

Dotted line PERPENDICULAR to mirror

Question 17

Incident ray

Answer 17

The ray moving towards the mirror

Question 18

Reflected ray

Answer 18

Ray that is reflected off mirror

Question 19

Point of incidence

Answer 19

Point on mirror where incident ray hits

Question 20

Angle of incidence

Answer 20

Angle between incident ray and normal

Question 21

Angle of reflection

Answer 21

Angle btw reflected ray and normal

Question 22

What is the law of reflection and what do scientists call the subjects infront of the mirror and in the mirror?

Answer 22

1. Law of reflection is Angle of Incidence = Angle of Reflection
2. Object in front of mirror is called the OBJECT. The likeness seen inside the mirror is called the image.

Question 23

Examples of concaved mirrors

Answer 23

Cosmetic mirrors, Hubble telescopes, Headlights

Question 24

Concave mirror

Answer 24

Reflecting surface that curves inward

Question 25

Principale axis

Answer 25

Line that's PERPINDICULAR to center of mirror

Question 26

Vertex

Answer 26

Point where PA and mirror and mirror

Question 27

Focal point (F)

Answer 27

Point where reflected rays intersect when all incident rays (IR) are parallel

Question 28

Center of curvature (C/2F)

Answer 28

Point that represents the centre of the mirror if it were a full circle.

Question 29

3 rays in concave ray diagrams?

Answer 29

1. Parallel - parellel line through, out from focul 2. Focal - In through focal out parallel 3. Vertex - Vertex point, equal, Law of reflection, equal angles

Question 30

Examples of convex mirror?

Answer 30

Parking garage mirrors, store security mirrors, Art, Blind spot mirrors/side mirrors

Question 31

Where do all reflected rays converge?

Answer 31

Behind the mirror

Question 32

Which mirror is LOST always the same for?

Answer 32

Convex mirrors

Question 33

Which type of mirrors only make virtual images?

Answer 33

Plane and Convex

Question 34

Which mirror makes your face appear bigger?

Answer 34

Convex mirrors

Question 35

Which colour has the highest frequency?

Answer 35

Violet has the highest. It goes inverse from lowest to highest eg, lowest is red, orange yellow green blue indigo and then violet.