Light travels in a straight line and the bouncing back of light after striking a surface is called reflection, so this Grade 8 sheet opens with rectilinear path and the first light behaviour. Dispersion and the retina follow among the answers.
Key Takeaways
Light travels in a straight line (Q1).
The bouncing back of light is called reflection (Q2).
Q5 records dispersion among the light answers.
Section A: Multiple Choice Questions (1 Mark Each)
Choose the correct option for each question.
1.Light travels in a ____ line.
(a) Straight(b) Curved(c) Zig-zag(d) Circular
2.The bouncing back of light after striking a surface is called:
6.In the human eye, the image of an object is formed on the:
(a) Retina(b) Cornea(c) Pupil(d) Lens
Section B: Short Answer Type Questions (2 Marks Each)
Show all steps clearly.
7.State the two laws of reflection.
8.Differentiate between a real image and a virtual image.
9.What is the blind spot in the human eye?
10.What is a kaleidoscope? Name the principle on which it works.
11.What is dispersion of light? Name the seven colours of the visible spectrum.
12.Why do we see our image in a plane mirror? Is the image laterally inverted?
13.What is the function of the iris and the pupil in the human eye?
14.Define the normal, the angle of incidence, and the angle of reflection with respect to a plane mirror.
Section C: Numericals & Word Problems (3 Marks Each)
Apply the concepts to solve the problems. Show all working.
15.A ray of light strikes a plane mirror at an angle of incidence of 40°. Find the angle between the incident ray and the reflected ray.
16.A ray of light makes an angle of 30° with the surface of a plane mirror. Find the angle of incidence and the angle of reflection.
17.A man stands 2 m in front of a plane mirror. How far is his image from him? If he moves 1 m towards the mirror, what is the new distance between him and his image?
18.An object is placed 30 cm in front of a plane mirror. Find the distance between the object and its image.
19.A ray of light falls normally (perpendicularly) on a plane mirror. What are the angles of incidence and reflection?
20.Light travels at a speed of 3 × 10⁸ m/s. Calculate the time taken by light to travel a distance of 900 km.
Answer Key
1. a) Straight
2. a) Reflection
3. a) Reflection
4. a) Virtual and erect
5. a) Dispersion
6. a) Retina
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.
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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 a straight line, option (a) in this worksheet (Q1).
What is the bouncing back of light called?
Reflection, option (a) in this worksheet (Q2).
What splits white light into colours?
Dispersion, option (a) in this worksheet (Q5).
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