Light

Question 1

What is the angle of incidence?

Answer 1

i, the angle an incoming ray makes with the normal

Question 2

What is an angle of reflection?

Answer 2

r, the angle a reflected ray makes with the normal

Question 3

What is the angle of refraction?

Answer 3

r, the angle a refracted ray makes with the normal

Question 4

What is a critical angle?

Answer 4

The angle of incidence of light that produces an angle of refraction of 90°

Question 5

What is diffuse reflection?

Answer 5

Reflection of light from an uneven surface

Question 6

What is an incident ray?

Answer 6

An incoming ray

Question 7

What is lateral inversion?

Answer 7

The sideways or left to right reversal of an image in a plane mirror

Question 8

What is the law of reflection?

Answer 8

The law stating that light is reflected at the same angle that it is the incident, i=r

Question 9

What is the normal?

Answer 9

An imaginary line that is drawn at right angles to the surface light is being reflected on

Question 10

What is a plane mirror?

Answer 10

A flat mirror

Question 11

What is refraction?

Answer 11

The bending of light as it enters or leaves different substances

Question 12

What is refractive index?

Answer 12

A measure of how easily light travels through a substance

Question 13

What is regular reflection?

Answer 13

Reflection of light on a very smooth surface producing a really clear image

Question 14

What is total internal reflection?

Answer 14

When light is completely reflected from the boundary of two substances, occurs when the angle of incidence is greater than the critical angle

Question 15

What is a virtual image?

Answer 15

A type of image formed when the rays of light do not meet but appear to in a mirror

Question 16

What is accommodation?

Answer 16

The ability of the lens of the eye to be able to change its shape to adjust its focus

Question 17

What is a concave lens?

Answer 17

A lens that curves inwards (

Question 18

What is a convex lens?

Answer 18

A lens that bulges outwards )

Question 19

What is the cornea?

Answer 19

A transparent covering over the iris, bends light into the lens

Question 20

What is focal length?

Answer 20

The distance from a lens to its focus

Question 21

What is the lens?

Answer 21

In the eye it is a flexible structure that contracts and relaxes to enable light to be focused on the retina

Question 22

What is long sighted-ness ( hyperopia ) ?

Answer 22

The inability to focus on close objects because the eyeball is too long

Question 23

What is the optic nerve?

Answer 23

A nerve that carries an electrical signal from the retina to the brain

Question 24

What is the retina?

Answer 24

A nerve tissue at the back of the eye, has rod and cone cells, light is converted to an electrical signal here

Question 25

What is short sighted-ness ( myopia ) ?

Answer 25

The inability to focus on distant objects because the eyeball is too short

Question 26

How does light travel?

Answer 26

As a wave, an electromagnetic wave

Question 27

Is light faster than sound?

Answer 27

Yes

Question 28

When light hits a surface it may be ;

Answer 28

Transmitted through it (transparent) Reflected off it (translucent) Absorbed into it (opaque)

Question 29

What is an object that emits light called?

Answer 29

Luminous

Question 30

Why does refraction occur?

Answer 30

Because light travels through substances at different speeds so when it enters something different it bends.

Question 31

What happens when light goes from a higher refractive index to a lower refractive index?

Answer 31

Light will bend away from the normal

Question 32

What happens when light goes from a lower refractive index to a higher one?

Answer 32

It bends towards the normal

Question 33

When going from air to water the light ...?

Answer 33

Bends towards the normal

Question 34

When light goes from water to air the light...?

Answer 34

Bends away from the normal

Question 35

What happens when you look in water?

Answer 35

The objects appear closer because light from things underwater bends away from normal when it leaves water and goes into air.

Question 36

Why can't you see underwater?

Answer 36

Because the light doesn't bend as much underwater so when you wear goggles it's clearer because there is air.

Question 37

What does a convex lens do?

Answer 37

Produces an enlarged virtual image

Question 38

What does a concave lens do?

Answer 38

Cause light to spread out

Question 39

What are the parts of the eye?

Answer 39

``` Aqueous humour Cornea Lens Ciliary body Conjunctiva Choroid Sclera Fovea centralis Optic nerve Eye muscles Vitreous humour Retina Iris Pupil Dilator muscle Sphincter muscle ```

Question 40

Why does your vision get worse as you get older?

Answer 40

Because your lenses become hard and inflexible not allowing you to see certain things

Question 41

What does the aqueous humour do?

Answer 41

Lies between the cornea and lens, clear and watery fluid produced by ciliary body to moisten the lens and cornea

Question 42

What does the ciliary body do?

Answer 42

The ciliary body makes the lens change shape to focus on things at different distances

Question 43

What is the conjunctiva?

Answer 43

A membrane that covers the sclera

Question 44

What is the choroid?

Answer 44

Has a rich blood supply and nourishes the retina

Question 45

What is the sclera?

Answer 45

Tough outer coating which protects the eye

Question 46

What is the vitreous humour?

Answer 46

Clear jelly like fluid between the lens and retina

Question 47

What are the eye Muscles?

Answer 47

They help move the eye in its socket

Question 48

What is the fovea centralis?

Answer 48

Responsible for sharp vision

Question 49

What is the iris?

Answer 49

Coloured part of the eye

Question 50

What is the dilator muscle?

Answer 50

Enlarges pupil to allow more light into the eye

Question 51

What is the sphincter muscle?

Answer 51

Makes pupil smaller allowing less light into the eye

Question 52

What is the pupil?

Answer 52

An opening in the iris which determines the amount of light entering the eye