Ray Optics and Optical Instruments Mock Test – Class 12 Physics

1. The main difference between magnification and resolution is that magnification describes

2. A graph is plotted for a thin lens with on the vertical axis and on the horizontal axis. From the thin lens formula, the graph has

3. In an astronomical telescope, the objective lens usually has

4. A ray is incident normally on one face of a rectangular glass slab. The lateral displacement after emerging from the second face is

5. When an object is placed at the principal focus of a convex lens, the refracted rays are

6. Two thin lenses of powers and are kept in contact. The equivalent power is

7. The optical quantity among the following that has no unit is

8. A spherical mirror has centre of curvature located in front of its pole . If incident light travels from left to right and the mirror faces the incident light, the sign of is

9. The tube length of an astronomical telescope in normal adjustment is , and its eyepiece focal length is . The objective focal length and magnifying power are

10. The following ray rules are written for spherical mirrors:

The correct rows are

11. For a real object placed anywhere in front of a concave lens in air, the image is formed

12. A simple microscope has focal length . Taking , its magnifying power for final image at the near point is

13. A ray inside a transparent medium of refractive index is incident on the medium-air boundary. If , the ray

14. An astronomical telescope has magnifying power in normal adjustment. If the eyepiece focal length is , the objective focal length should be

15. For an astronomical telescope in normal adjustment, the final image is formed

16. In an astronomical telescope, the objective forms the first image of a distant object approximately

17. A student is using for a spherical refracting surface. Consider the statements:
I. belongs to the medium from which light is incident.
II. belongs to the medium into which light refracts.
III. is positive or negative according to the side of the centre of curvature.
IV. The signs of , , and may be ignored if distances are written in .
The suitable set is

18. A microscope is required to distinguish two very close points in a specimen. The resolution is improved by using

19. A convex mirror has focal length . A real object is placed in front of it. The image distance is

20. A convex lens is used as a magnifying glass. The object must be placed

21. Diffraction limits the resolving power of a telescope because light from a point object forms

22. A learner writes for a concave mirror whose reflecting surface faces the incoming light. The most precise correction is

23. The magnifying power of an astronomical telescope when the final image is at the near point is

24. A spherical refracting surface separates two transparent media. Its radius of curvature is measured from

25. Use the arrangement described below. A lens has optical centre , incident light travels from left to right, and an object is placed on the left side of . A real image is formed on the right side of the lens. The signs of and are

26. The refraction formula at a spherical surface is different from the mirror formula mainly because

27. A graph is described for a convex mirror with object distance magnitude increasing along the horizontal axis and image distance behind the mirror along the vertical axis. As the object becomes very far away, the image position approaches

28. A thin lens forms an image with . The meaning of this result is that the image is

29. An equiconcave lens in air has , , and . Its focal length is

30. A simple microscope is required to give magnifying power when the final image is at the near point. Taking , the focal length should be

31. A magnifier has power . Taking , its near-point magnifying power is

32. Consider these statements about the human eye and vision correction:
I. A normal eye has near point approximately .
II. Myopia is corrected by a concave lens.
III. Hypermetropia is corrected by a convex lens.
IV. Astigmatism is corrected only by increasing the prism angle of spectacles.
The suitable set is

33. A claim says, “A myopic eye should be corrected by a convex lens because a distant object sends parallel rays.” The better response is that a myopic eye needs

34. The far point of a normal eye is

35. The iris in the human eye mainly controls

36. A white beam entering a water droplet separates into colours because

37. A compound microscope has , , , and . Its approximate magnifying power for final image at the near point is

38. Two thin lenses of focal lengths and are separated by . The equivalent focal length of the system is

39. A compound microscope uses an objective of focal length and an eyepiece of focal length . If and the final image is at infinity, the magnifying power is

40. The branch of optics used for ordinary mirror and lens image diagrams relies most directly on

41. A concave lens forms an image one-third the height of a real object. If the object is in front of the lens, the focal length is

42. In a prism ray diagram, the angle of deviation is measured between

43. The angle of prism is the angle between

44. A convex lens forms an image of an object placed beyond . The image is formed

45. A learner has to select a formula for each situation:

The acceptable rows are

46. A table lists possible design choices:

The suitable rows are

47. For a medium-air boundary, . If increases from to , the critical angle

48. A thin prism in air has angle and refractive index . The approximate deviation of a monochromatic ray is

49. A small object is brought closer to the eye, and it appears larger until the eye can no longer focus it clearly. The limiting nearest distance for clear vision in a normal eye is called

50. In an experiment, is plotted on the vertical axis and on the horizontal axis for refraction from medium to medium . The slope of the straight line is