KS3 Science Quiz - Light 01 (Questions)

This KS3 Science quiz takes a look at light. Light travels as waves and comes from luminous objects. Most luminous objects are luminous because they are hot. It is possible to have luminous objects that are cold, for example, glowsticks. These rely on chemical reactions and not heat to produce their light. Light can travel through transparent or translucent objects. We can see objects that are not luminous because everything reflects light to a lesser or greater degree. The reflected light rays bounce off objects and into our eyes.

The way that light reflects from objects, including mirrors, is predictable. It can be worked out using ray diagrams. You start by drawing the surface off which the light is reflected. Then you draw in the normal. This is an imaginary line at ninety degrees (a right angle) to the surface. The normal is drawn as a dotted or dashed line to show that it is different to a ray of light. Next you draw the incident ray at the correct angle (measured from the normal and not from the reflecting surface). The reflected ray is then drawn in at the same angle, but on the other side of the normal.

1. Light travels in:
[ ] Circular lines
[ ] Straight lines
[ ] Wavy lines
[ ] Zig zag lines
2. Which of the following statements about light is not false?
[ ] Fastest in a vacuum
[ ] Fastest in air
[ ] Fastest in water
[ ] Slower than sound
3. Light can travel through which of the following?
[ ] A luminous material
[ ] A mirror
[ ] A translucent material
[ ] An opaque material
4. Which of the following is translucent?
[ ] A mirror
[ ] Air
[ ] Greaseproof paper
[ ] The moon
5. Which of the following is NOT luminous?
[ ] A burning candle
[ ] A car headlight (switched on)
[ ] The Moon
[ ] The Sun
6. Which of the following statements is the correct reason we can see objects that are NOT luminous?
[ ] Our eyes give out light
[ ] They bend light into our eyes
[ ] They reflect light into our eyes
[ ] They shine light into our eyes
7. We usually look at our reflection in a flat mirror. This type of mirror is a .......
[ ] Bi-concave mirror
[ ] Concave mirror
[ ] Convex mirror
[ ] Plane mirror
8. In a flat mirror, the angle of incidence is equal to what?
[ ] The angle of emergence
[ ] The angle of reflection
[ ] The angle of refraction
[ ] The angle of transmission
9. Objects with a smooth surface give what type of reflection?
[ ] Diffuse reflection
[ ] Irregular reflection
[ ] No reflection
[ ] Regular reflection
10. In a ray diagram, a normal is a line drawn at what angle to the surface?
[ ] 180° to the mirror's surface
[ ] 45° to the mirror's surface
[ ] 60° to the mirror's surface
[ ] 90° to the mirror's surface
KS3 Science Quiz - Light 01 (Answers)
1. Light travels in:
[ ] Circular lines
[x] Straight lines
[ ] Wavy lines
[ ] Zig zag lines
It changes direction when it meets a surface that reflects it
2. Which of the following statements about light is not false?
[x] Fastest in a vacuum
[ ] Fastest in air
[ ] Fastest in water
[ ] Slower than sound
Light travels at almost 300,000,000 metres per second in a vacuum
3. Light can travel through which of the following?
[ ] A luminous material
[ ] A mirror
[x] A translucent material
[ ] An opaque material
Light can travel through translucent material
4. Which of the following is translucent?
[ ] A mirror
[ ] Air
[x] Greaseproof paper
[ ] The moon
Translucent means allowing light to pass through but diffusing it so that people and objects on the opposite side are not clearly visible. A frosted window is translucent but not transparent. Tracing paper is another example of a translucent material
5. Which of the following is NOT luminous?
[ ] A burning candle
[ ] A car headlight (switched on)
[x] The Moon
[ ] The Sun
A luminous object gives out light. The Moon reflects light but does not give out light of its own
6. Which of the following statements is the correct reason we can see objects that are NOT luminous?
[ ] Our eyes give out light
[ ] They bend light into our eyes
[x] They reflect light into our eyes
[ ] They shine light into our eyes
If you went deep into a cave, a long way from the entrance and turned off your torch, you would not be able to see your hand if it was right in front of your face because there would not be enough light reflected into your eyes
7. We usually look at our reflection in a flat mirror. This type of mirror is a .......
[ ] Bi-concave mirror
[ ] Concave mirror
[ ] Convex mirror
[x] Plane mirror
Concave and convex mirrors are curved
8. In a flat mirror, the angle of incidence is equal to what?
[ ] The angle of emergence
[x] The angle of reflection
[ ] The angle of refraction
[ ] The angle of transmission
In actual fact, the same is true of curved mirrors but it is much more difficult to draw and measure
9. Objects with a smooth surface give what type of reflection?
[ ] Diffuse reflection
[ ] Irregular reflection
[ ] No reflection
[x] Regular reflection
Rough surfaces give diffuse reflection
10. In a ray diagram, a normal is a line drawn at what angle to the surface?
[ ] 180° to the mirror's surface
[ ] 45° to the mirror's surface
[ ] 60° to the mirror's surface
[x] 90° to the mirror's surface
It is also drawn touching the surface at the same point as the ray of light