#### Optics Important Questions

10th Standard

Reg.No. :
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Science

Time : 01:00:00 Hrs
Total Marks : 50
5 x 1 = 5
1. Power of a lens is –4D, then its focal length is

(a)

4m

(b)

–40m

(c)

–0.25 m

(d)

–2.5 m

2. In a myopic eye, the image of the object is formed

(a)

behind the retina

(b)

on the retina

(c)

in front of the retina

(d)

on the blind spot

3. The eye defect ‘presbyopia’ can be corrected by

(a)

convex lens

(b)

concave lens

(c)

convex mirror

(d)

Bi focal lenses

4. Which of the following lens would you prefer to use while reading small letters found in a dictionary?

(a)

A convex lens of focal length 5 cm

(b)

A concave lens of focal length 5 cm

(c)

A convex lens of focal length 10 cm

(d)

A concave lens of focal length 10 cm

5. Violet and red light ______ wavelengths.

(a)

lowest, highest

(b)

highest, lowest

(c)

same

(d)

standard

6. 5 x 1 = 5
7. The path of the light is called as_____________

()

ray

8. The refractive index of a transparent medium is always greater than__________

()

one

9. Angle of refraction is _____ for red and _____ for violet.

()

smallest, highest

10. Refractive index of a medium is dependent on ______ of the light.

()

wavelength

11. The interacting particle of the medium is called as _______

()

scatterer

12. 5 x 1 = 5
13. Ciliary muscles

14. (1)

Power accommodation

15. Myopia

16. (2)

$(\mu -1)\left( \frac { 1 }{ { R }_{ 1 } } -\frac { 1 }{ { R }_{ 2 } } \right)$

17. violet light

18. (3)

Far point comes closer

19. red light

20. (4)

highest wavelength

21. Lens maker's formula

22. (5)

highest frequency

5 x 2 = 10
23. Why does the sky appear in blue colour?

24. Why are traffic signals red in colour?

25. What are the conclusions obtained from laws of refraction?

26. How is a rainbow formed?

27. Name and explain the types of scattering?

28. 5 x 3 = 15
29. State the laws of refraction.

30. Explain Raman Scattering.

31. Write the sign convention for lenses.

32. Explain the types of Telescope.

33. Explain the refraction of light through a glass prism.

34. 2 x 5 = 10
35. Differentiate the eye defects: Myopia and Hypermetropia.

36. Explain the construction and working of a 'Compound Microscope'.