Primary 6 PSLE Science Light Quiz

Primary 6 PSLE Science Quiz - Light (Answer Key)

Total Marks: 40
Topic: Light
Note: Syllabus-first content from LLM-inferred templates; not past-year derived.

Section A Answers (1 mark each)

1. straight
Teaching note: Light travels in a straight line. This is why shadows have sharp edges when the source is small.

2. B) A lit candle
Teaching note: A source of light makes its own light. The Moon, mirror, and wall only reflect light from other sources.

3. reflected
Teaching note: A smooth mirror reflects light in a regular way so we see an image.

4. opaque
Teaching note: Opaque objects block light completely; no light passes through.

5. travels in a straight line (and cannot bend around objects)
Teaching note: Light moves straight, so an object blocks it and leaves a dark shadow behind.

6. B) Clear glass
Teaching note: Transparent materials let most light pass through so we can see through them.

7. refraction
Teaching note: Refraction is the bending of light when it passes from one material (air) to another (water) at an angle.

8. reflects; absorbs
Teaching note: A red apple reflects red light to our eyes and absorbs the other colours, so it looks red.

9. violet
Teaching note: The spectrum order is Red, Orange, Yellow, Green, Blue, Indigo, Violet (ROYGBIV).

10. two
Teaching note: A simple periscope uses two plane mirrors at 45° to bounce light from one end to the viewer’s eye.

Section B Answers (2 marks each)

11. (2 marks)

• The room light sends out light in straight lines. (1 mark)
• Light reflects from the book into the person’s eyes, so the person sees the book. (1 mark)
  Teaching note: We see non-luminous objects only when light from a source reflects off them into our eyes.

12. (2 marks)

• The shadow becomes larger. (1 mark)
• Moving the ball closer to the light makes the light blocked over a bigger area on the screen. (1 mark)
  Teaching note: Closer to source → wider cone of blocked light → bigger shadow.

13. (2 marks)
(i) Transparent lets light pass through; opaque does not. (1 mark)
(ii) We can see through transparent material; we cannot see through opaque material. (1 mark)
Common mistake: Confusing translucent (some light, blurry) with transparent.

14. (2 marks)

• Light is reflected by the mirror. (1 mark)
• The angle of reflection equals the angle of incidence (light bounces off at the same angle). (1 mark)
  Teaching note: Plane mirrors give regular reflection.

15. (2 marks)

• Light from the pool bottom bends (refracts) when leaving water into air. (1 mark)
• This makes the bottom seem higher, so the pool looks shallower. (1 mark)

16. (2 marks)

• The leaf absorbs the other colours of light. (1 mark)
• Only green light is reflected to our eyes. (1 mark)

Section C Answers (3 marks each)

17. (3 marks)

• Light from the part of the ruler in water travels from water to air. (1 mark)
• It refracts (bends) because water and air have different densities. (1 mark)
• The bent light makes the ruler look broken at the surface. (1 mark)
  Image note: Diagram must show ruler bent at surface; eye on left sees apparent break.

18. (3 marks)

• The bright light sends straight light rays towards the sheet. (1 mark)
• Opaque puppets block the light, forming dark shadows on the sheet. (1 mark)
• If puppets were not opaque, light would pass through and no clear shadow would form. (1 mark)

19. (3 marks)

• White light is made of many colours mixed together. (1 mark)
• The prism refracts each colour by a different amount because they travel at different speeds in glass. (1 mark)
• This separates them into a spectrum from red to violet. (1 mark)
  Image note: Bands must show red to violet order.

20. (3 marks)

• The mirror reflects the sunlight in a new direction. (1 mark)
• The boy aims the reflected beam into the dark corner. (1 mark)
• Light enters the corner and reflects off surfaces to our eyes, making it brighter. (1 mark)