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Practice Test - 1

Welcome to your Ray optics and optical instrume

1. 
Light through glass t, μ. Time?

2. 
Convex + concave lenses, f = 25 cm. Power?

3. 
Glass plate 6 cm thick. Object 8 cm in front, image 12 cm behind. Find μ.

4. 
Light hits glass at 45°, which μ for total internal reflection?

5. 
Plano-convex, R = 10 cm, μ = 1.5. Plane surface silvered. Find focal length.

6. 
Two thin lenses F, filled with glycerin (μ = 1.5), net focal length F₂?

7. 
Equiconvex lens, cut along principal axis → power of one part?

8. 
Light travels from bottom of beaker (μ = 1.33). Speed in liquid?

9. 
Red & green rays fall on glass; exit face?

10. 
Lens with focal f and aperture d. Image intensity ∝ ?

11. 
A beam is reflected normally from a mirror. The mirror rotates by angle θ, and the reflected spot moves by distance y. Angle θ is given by

12. 
Converging lens: f measured for violet, green, red. Correct relation?

13. 
Convex lens in liquid (μ = lens). Focal length?

14. 
Light has f = 2×10¹⁴ Hz and λ = 5000 Å. μ = ?

15. 
Time sunlight takes to pass window glass of 4 mm (μ = 3/2)?

16. 
Light enters glass at angle i. No lateral shift if

17. 
A person is 6 ft tall. Min. mirror length to see entire self?

18. 
Equiconvex, f = 10 cm. Sun rays focus on paper. D = 1.39×10⁹ m, r = 1.5×10¹¹ m. Image size?

19. 
Point source at 4 m below water (μ = 5/3). Minimum disc diameter to block light?

20. 
Biconvex lens: R = 20 cm, object 2 cm at 30 cm. Image?

21. 
Light frequency = 100 Hz. Wavelength?

22. 
A 10 cm rod lies along the principal axis of a concave mirror. Closer end is 20 cm away; focal length is 10 cm. Find length of image.

23. 
λ = 5460 Å in air. Glass (μ = 1.5). λ in glass?

24. 
Two identical plano-convex lenses (μ = 1.5, R = 20 cm), liquid in between (μ = 1.7). Net focal length?

25. 
For TIR in rectangular slab with angle 45°, find μ

26. 
Double convex lens: focal 25 cm, R₂ = 2×R₁, μ = 1.5. Find R₁

27. 
Image of equal size at distance d using convex lens. f = ?

28. 
In total internal reflection, angle of refraction at critical angle is

29. 
Convex lens (f₁), concave mirror (f₂), image at ∞. Find d.

30. 
Ray optics valid when dimensions are

31. 
Equiconvex cut in two ways: XOX′ and YOY′. f′, f″?

32. 
Two lenses f₁ and f₂, coaxial. Power?

33. 
Object at 30 cm from lens (f = 20 cm), concave mirror makes upright image. Mirror radius?

34. 
Not due to total internal reflection?

35. 
Biconvex in liquid (μ = glass) acts as?

36. 
Light (ν, λ) enters glass (μ). New values?

37. 
Wavelength in glass (μ = 1.5) if incident λ = 6×10⁻⁷ m?

38. 
Reddish sunset is due to

39. 
Converging beam to diverging lens. Rays focus 5 cm past lens. Object rays meet at 15 cm before. Focal length?

40. 
Air bubble in glass (μ = 1.5), appears 2 cm deep. Actual depth?

41. 
Plano-convex fits into plano-concave (μ₁, μ₂). Focal length?

42. 
Two mirrors at 60°, object placed between. Number of images?

43. 
Two plane mirrors are inclined at 70°. Incident ray reflects and becomes parallel to first mirror. Find angle of incidence θ.

44. 
Plano-convex: R = 60 cm, μ = 1.6. Focal length?

45. 
Match magnification to mirror: m = -2, m = -1/2