Light reflection and refraction Worksheet-12

Light reflection and refraction Worksheet-12

1. What is the range of wavelength of visible light ?

2. Can light travel in vacuum ? If yes, with what speed ?

3. What is the speed of light in air ?

4. What is a ray of light ?

5. What is meant by pencil of light ?

6. Name the best reflector of light.

7. Can normal to a mirror be taken as a normal ray ?

8. What is angle of incidence ?

9. What is meant by angle of reflection ?

10. What is the angle of incidence when a ray falls normally on a mirror ?

11. Do the laws of reflection change, when we use a spherical mirror instead of a plane mirror ?

12. Can an object be virtual ?

13. Can a real Image be taken on a screen ?

14. Do light rays actually pass through a real image ?

15. Do light rays actually pass through a virtual image ?

16. Name two types of spherical mirrors.

17. How do you draw normal to a spherical mirror at a particular point ?

18. Which of the two mirrors is diverging : concave or convex ?

19. Which of the two mirrors is converging : concave or convex ?

20. What is the relation between focal length and radius of curvature of a concave mirror ? Does the same relation hold for a convex mirror ?

Answer:

1. From 4 × 10^–7 m to 8 × 10^–7 m.

2. Yes, 3 × 10^–8 m/s.

3. 3 × 10^–8 m/s.

4. The straight line path along which light travels is called ray of light.

5. A narrow beam of light is called pencil of light.

6. Silver metal is the best reflector of light.

7. No.

8. Angle of incidence is the angle between the incident ray and normal to the mirror.

9. The angle between the reflected ray and normal to the mirror.

10. ∠i = 0°.

11. No.

12. Yes.

13. Yes.

14. Yes

15. No, they only appear to pass through a virtual image.

16. Concave mirror and convex mirror.

17. Join that particular point to the centre of curvature of the mirror.

18. Convex mirror

19. Concave mirror

Yes, the same relation holds for a convex mirror.