Ray Optics and Optical Instruments Mock Test – Class 12 Physics

1. A candle is placed at of a convex lens. Its image is formed

2. An astronomical telescope has , , and . Its magnifying power for final image at the near point is

3. Use the arrangement described here: a concave mirror has its pole at , and the incident light travels from left to right toward the mirror. An object is placed on the left side of . Under the usual Cartesian convention, the sign of is

4. In the New Cartesian sign convention commonly used for mirrors and lenses, if incident light travels from left to right, distances measured to the left of the origin are generally

5. When an object is placed at the principal focus of a concave mirror, the reflected rays are

6. A student claims that a convex mirror can form a real image of a real object if the object is taken very far away. The claim is

7. The objective in a compound microscope and the objective in an astronomical telescope differ mainly because the microscope objective has

8. The image formed by a convex mirror is always diminished for a real object because

9. A real object is placed in medium on the left side of a spherical refracting surface, and light travels from left to right. The object distance is generally

10. A plano-convex lens in air has refractive index . Its curved surface has radius , and the other surface is plane. The focal length is

11. The spectacle lens used to correct myopia is

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

13. A compound microscope is redesigned by reducing while keeping , , and unchanged. Its magnifying power increases mainly because

14. The formula and the formula are used for different instruments. The first applies to a

15. A telescope is used to observe a faint star cluster. A larger objective aperture helps primarily by

16. An object is placed between and in front of a concave mirror. The image is expected to be

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

18. The eyepiece in a compound microscope forms the final image by treating the intermediate image as

19. If the same compound microscope has , , , and the final image is formed at infinity, the approximate magnifying power is

20. Assertion: At minimum deviation, the refractive-index formula for a prism can be written using only and .
Reason: At minimum deviation, and , so Snell's law can be expressed in terms of and .

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

22. A table of general optical-instrument terms is shown below:

The acceptable rows are

23. A reflecting telescope uses a concave mirror as the objective mainly because a mirror objective

24. In ray optics, a straight line with an arrow is drawn to represent a light ray. The arrow mainly shows

25. Three thin lenses of powers , , and are kept in contact. The equivalent focal length is

26. A compound microscope has objective focal length , eyepiece focal length , tube length , and near point . For final image at the near point, the approximate magnifying power is

27. In microscope resolution, using blue light instead of red light can be helpful because blue light has

28. The eyepiece of an astronomical telescope mainly

29. Consider the following statements about refraction:
I. The angles in Snell's law are measured from the normal.
II. At a boundary, the frequency of a light wave remains unchanged.
III. If , an obliquely incident ray bends toward the normal in medium .
The suitable choice is

30. A Galilean telescope differs from the usual astronomical telescope because its eyepiece is

31. A spherical refracting surface has , , , and . If the object height is , the image distance and image height are

32. A graph is drawn for identical-shape convex lenses in air with on the vertical axis and on the horizontal axis. The graph is expected to be

33. A convex lens of focal length and a concave lens of focal length are separated by . The equivalent focal length is

34. 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

35. A prism has . At minimum deviation, the refractive index is . If the prism is used as a thin-prism approximation instead, the approximate deviation for the same material and is

36. Two plane mirrors are arranged at right angles, and a small object is placed symmetrically between them. The expected number of images is

37. Consider these statements about a plane mirror:
I. The image distance equals the object distance.
II. The image is virtual and erect.
III. The image is always twice as large as the object.
IV. The image shows lateral inversion.
The correct set is

38. In total internal reflection, the reflected ray at the boundary

39. For a simple microscope used with relaxed eye, the final image is at infinity. Its magnifying power is

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

41. A screen is placed at the position where reflected rays from a concave mirror actually meet. The bright image on the screen is an example of

42. A mirror produces a virtual erect image of height from an object of height . The magnification is

43. A ray is incident normally on a water surface from air. The direction of the refracted ray is

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

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

46. A student measures the angle between an incident ray and a plane mirror surface as . The reflected ray will make what angle with the normal?

47. 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

48. In the usual sign language for image height, an image formed below the principal axis has height

49. In a desert mirage, the lower air layer near the hot ground has

50. A structure-function record for the human eye is given below:

The suitable rows are