Light travels in straight lines and the Sun is the source of light listed, so this Year 7 sheet opens with rectilinear travel and the sky's own lamp. An opaque object blocking light, plus transparent and translucent answers, follow in the key.
Key Takeaways
Light travels in straight lines (Q1).
The Sun is a source of light (Q2).
An opaque object blocks light (Q3).
Section A: Multiple Choice Questions (1 Mark Each)
6.We see a lit candle because light from the candle...
(a) reflects off our eyes(b) travels straight into our eyes(c) is blocked by air(d) travels in curved paths
Section B: Short Answer Type Questions (2 Marks Each)
Show all steps clearly.
7.State the rule that describes how light travels from a source.
8.What is a luminous object? Give one example.
9.Explain why the Moon is not a light source.
10.What is a shadow and how is it formed?
11.State two differences between a transparent material and an opaque material.
12.When during the day is a shadow longest? Explain why.
13.What happens to the size of a shadow when an object is moved closer to the light source?
14.Give one practical use of shadows.
Section C: Numericals & Word Problems (3 Marks Each)
Apply the concepts to solve the problems. Show all working.
15.Light travels at a speed of 300,000 km/s. Use distance = speed × time to calculate how far light travels in 2 s.
16.A satellite sends a light signal 900,000 km to Earth. Use time = distance ÷ speed with speed = 300,000 km/s to calculate how long the signal takes to arrive.
17.How far does light travel in half a second if its speed is 300,000 km/s?
18.The Sun is 150,000,000 km from Earth. Use time = distance ÷ speed to calculate how long light takes to reach Earth from the Sun.
19.Light from the Sun takes 8 minutes to reach Earth. First convert 8 minutes to seconds, then use distance = speed × time with speed = 300,000 km/s to calculate the distance.
20.A 1.5 m tall child casts a shadow 0.5 m long. At the same time a building casts a shadow 2 m long. Use building height = (child height ÷ child shadow) × building shadow to calculate the height of the building.
Answer Key
1. b) straight lines
2. c) the Sun
3. b) an opaque object blocks light
4. c) transparent
5. b) translucent
6. b) travels straight into our eyes
7. Refer to solution guide.
8. Refer to solution guide.
9. Refer to solution guide.
10. Refer to solution guide.
11. Refer to solution guide.
12. Refer to solution guide.
13. Refer to solution guide.
14. Refer to solution guide.
15. Refer to solution guide.
16. Refer to solution guide.
17. Refer to solution guide.
18. Refer to solution guide.
19. Refer to solution guide.
20. Refer to solution guide.
End of Worksheet
People Also Ask
How does light travel?
In straight lines, option (b) in this worksheet (Q1).
Which of these is a source of light?
The Sun, option (c) in this worksheet (Q2).
What happens when an opaque object blocks light?
A shadow forms — option (b) in this worksheet (Q3).
Stuck on a similar problem? Clear your next doubt instantly with the Doubt Solver.
Browse more free worksheets for IGCSE Year 7.