Light

Question 1

Energy

Answer 1

Is the ability to do work i.e move. Unit of energy is the joule

Question 2

Plants use of light

Answer 2

To make food (photosynthesis)

Question 3

Luminous

Answer 3

Objects that give off light are called luminous objects e.g. The Sun, Lightbulb, candle.

Question 4

Light

Answer 4

is a form of energy

Question 5

Light travels in straight lines

Answer 5

we can show this by blocking light from a bulb with card

Question 6

Light does not travel around corners

Answer 6

Blocking light leads shadows

Question 7

solar eclipse

Answer 7

occurs when the moon passes between the sun and the earth

Question 8

Lunar eclipse

Answer 8

Occurs when the earth is between the sun and the moon, the moon is in the earths shadow

Question 9

Reflection of light

Answer 9

Occurs when it bounces off a surface

Question 10

Regular reflection

Answer 10

Shiny, smooth surface eg. mirror-regular reflection, the rays are reflected, the rays are reflected back at the same angle

Question 11

Irregular reflection

Answer 11

Rough surface eg. ball of tin foil-irregular reflection

Question 12

Concave or diverging mirrors

Answer 12

• telescopes, make up and shaving mirrors

* can enlarge the image

Question 13

Convex or converging mirrors

Answer 13

• side mirror in cars, security mirrors in shops

* small, upright image with a wider field of Vision

Question 14

Refraction

Answer 14

• The bending of light as it goes from one medium to another eg. air to water
• light rays are refracted towards the denser material

Question 15

Lenses

Convex or converging lens

Answer 15

• Used to bring rays together

* used to fix long sightedness, or hypermetropia

Question 16

lenses

concave or diverging lens

Answer 16

• used to spread rays apart

* used to fix short sightedness, or myopia

Question 17

White light

Answer 17

• white light is not really white

* it is a mixture of the 7 colours of the spectrum