Topic 10 Visible Light

Question 1

The properties of light are: (list three properties)

Answer 1

Light is emitted by luminous objects
Light travels in straight lines
Light travels much faster than sound

Question 2

The change in direction of a wave passing from one medium to another caused by it’s change in speed.

Answer 2

Refraction

Question 3

Spreading of something over an area.

Answer 3

Dispersion

Question 4

Light travels to the material and is unable to travel any further.

Answer 4

Absorbed light

Question 5

Light that has changed direction, but continues to travel in the original material.

Answer 5

Reflected light

Question 6

Length of one wave pattern.

Answer 6

Wavelength

Question 7

Number of waves that move past a certain point in one second

Answer 7

Frequency

Question 8

Materials that allow all light to pass through.

Answer 8

Transparent

Question 9

Let light through but scatter it.

Answer 9

Translucent

Question 10

Materials that do not let light through (they absorb or reflect the light).

Answer 10

Opaque

Question 11

To send (as in sound or light). It also means light passing through an object.

Answer 11

Transmit

Question 12

The order of colours in the visible spectrum:

Answer 12

Red, Orange, Yellow, Green, Blue, Indigo, Violet

Question 13

Light ray which hits the surface.

Answer 13

Incident ray

Question 14

Ray which is reflected from the surface.

Answer 14

Reflected ray

Question 15

Imaginary line drawn perpendicular to the surface.

Answer 15

Normal line

Question 16

Angle between the incident ray and normal line.

Answer 16

Angle of incidence

Question 17

The angle between the reflected ray and normal line

Answer 17

Angle of reflection

Question 18

The colour of light which is refracted the least by a triangular prism.

Answer 18

Red

Question 19

The colour of light which is refracted the most by a triangular prism.

Answer 19

Violet

Question 20

A lens which has two sides that curve inwards.

Answer 20

Biconcave

Question 21

A lens which has one side that curves outward.

Answer 21

Convex

Question 22

Shadows: an object far from a light source makes a …………………….. shadow.

Answer 22

small

Question 23

Shadows: an object close to a light source makes a …………………. shadow.

Answer 23

big

Question 24

The law of reflection

Answer 24

The angle of incidence is equal to the angle of reflection.

Question 25

At a cricket match we see the bat hit the ball before we hear the ‘crack’ because…

Answer 25

light travels faster than sound.

Question 26

If light moves from air to glass, the light is refracted …………………………. the normal.

Answer 26

towards

Question 27

If light moves from water to air, the light is refracted ……………………. the normal

Answer 27

away from

Question 28

The part of the eye that transmits information from the retina to the brain.

Answer 28

Optic nerve

Question 29

The hole in the centre of the iris that controls how much light enters the eye.

Answer 29

pupil

Question 30

In bright light the pupil …………………… in size.

Answer 30

decreases

Question 31

In dim light the pupil ……………………….. in size.

Answer 31

increases

Question 32

The protective front covering of the eye.

Answer 32

cornea

Question 33

The sensory layer at the back of the eye.

Answer 33

retina

Question 34

When light hits a rough surface, the light is …………………………

Answer 34

scattered

Question 35

True or False: A black object appears black because it reflects black light into your eye.

Answer 35

False

Question 36

True or False: A white object appears white because it reflects the entire visible spectrum into your eye.

Answer 36

True

Question 37

True or False: A red object appears red because it absorbs all the colours of light, except red, which it reflects into your eye.

Answer 37

True