### Refraction of Light at Curved Surfaces

MULTIPLE CHOICE QUESTIONS

1. Every lens has ......... focal points.
A) one          B) two            C) three              D) infinite

2. A lens should have atleast ......... curved surfaces.
A) 1              B) 2                C) 3                      D) None of these

3. The focal length of a lens depends on ........
B) Material of the lens
C) Medium in which the lens is placed
D) All the above

4. Which one of the following materials cannot be used to make a lens.
A) Water        B) Glass           C) Plastic          D) Clay

5. Which of the following lens act as converging lens.
A) Biconvex lens                             B) Plano convex lens
C) Concavo Convex                        D) Biconcave lens

6. Which of the following lens is called as diverging lens.
A) Convex        B) Concave         C) Plano Concave      D) Plano Convex

7. If the convex lens is in water its focal length.
A) remain same    B) decreases      C) increases           D) None

8. An air bubble inside water behaves as a ......... lens.
A) Biconvex lens                   B) Biconcave lens
C) Plano convex lens              D) Plano concave lens

9. Biconvex lens 10. Biconcave lens 11. Lens formula for a convex lens. 12. Which of the following is the lens maker's formula. 13. The focal length of a lens is given by  A) Convex lens                                     B) Plano convex lens
C) Biconvex lens                                  D) Plano concave lens A) Concave lens                                         B) Convex lens
C) Plano concave lens                               D) Plano convex lens

16. The number of images formed by a lens made up of three different material is
A) 1               B) 2           C) 3               D) 4 A) convex, concave lenses              B) concave, convex lenses
C) biconvex lenses                           D) biconcave lenses A) Concave lens                                B) Convex lens
C) Plano - Concave lens                   D) Concavo - Convex lens

19. A Concave lens can be represented by a symbol. 20. A Convex lens can be represented by a symbol. 21. The midpoint of lens is called ..........
A) focus                               B) centre of curvature
C) optical centre                 D) None of these

22. Which of the following matching is incorrect? 23. Which of the following matching is incorrect.
A) Parallel beam of light rays convergent - convex lens.
B) Parallel beam of light rays divergent - concave lens.
C) The point of convergence - focus.
D) The point of divergence - centre of curvature.

24. Which of the following sentence is incorrect.
A) A lens has two radius of curvature.
B) The mid point of a thin lens is called optic centre of lens.
C) A lens has one focal point.
D) The distance between focus and optic centre is known as focal length.

25. Convex lens is used in the making of microscope due to ...........
A) it gives diminished image.
B) it gives magnified virtual image same side of the object.
C) it gives real image behind the screen.
D) it gives magnified image opposite side of the lens.

26. .......... lens is used in the making of microscope.
A) concave         B) convex     C) concave -convex   D) plano - convex

27. What type of optical instrument will you use for reading a page in small print?
A) Biconcave lens                          B) Biconvex lens
C) Plano - concave lens                D) Concavo - convex lens

28. A Convex lens is placed in water. The focal length will
A) remain same      B) decreases      C) increases      D) none of the above

29. The lens which can form real and virtual images in air is
A) Biconvex       B) Biconcave   C) Plano -concave        D) Plano - convex

30. Virtual image form .......... side of lens.
A) back              B) front            C) other               D) object

31. Real image form .......... side of lens.
A) front             B) back          C) other               D) object

32. .......... image cannot be captured on screen.
A) Inverted      B) Erected          C) Virtual           D) Real

33. Which of the below lens always forms a virtual, diminished image
A) convex lens   B) concave lens     C) double concave     D) plano - concave

34. The pole is also called as
A) Focus                                      B) Focal length
C) Optical centre                          D) Centre of curvature

35. A lens is bounded by two spherical surfaces curved inward is called
A) Double convex lens                  B) Double concave lens
C) Plane concave lens                   D) Plane convex lens

36. The line joining the centre of curvature and the pole is called
A) Principal axis                         B) Focal length
C) Radius of Curvature                D) Incident ray

37. Any ray passing through the principal axis is
A) Deviated                                B) Undeviated
C) Parallel ray                             D) Perpendicular ray

38. A light ray incident on curved surface travelling from rarer medium to denser medium bends .............. the normal.
A) towards          B) away from         C) parallel to            D) None

39. If an equi convex lens of focal length 'f' is cut into two halves along a plane passing through the principal axis then the focal length of each part of the lense is ............
A) B) 2f             C) f            D) 4f

40. In the above diagram when an equi convex lense of focal length 'f' is cut into two halves along a plane passing through the principal axis then the focal length of each part of the lens is
A) Remains same                            B) Double
C) Halved                                         D) None of these

41. In the above diagram when a lens of focal length 'f' is cut into two equal halves perpendicular to principal axis then the focal length of each part of the lens is ..................
A) Remains same                                               B) Double
C) Halved                                                             D) None of these

42. When a lense of focal length 10 cm is cut into two equal halves perpendicular to principal axis then the focal length of each part of lense is .......
A) 5 cm       B) 10 cm       C) 20 cm        D) None of these

43. An object is placed 12 cm from a converging lens of focal length 12 cm. The image is formed at a distance of
A) 6 cm                B) 12 cm          C) 36 cm            D) Infinity

44. The radii curvature of a double convex lens are 10 cm and 10 cm. Its refractive index is 1.5. The focal length is
A) 0.1 cm             B) 0.01 cm        C) 10 cm          D) None

45. Which of the following is true in case of virtual image?
A) Obtained on screen                            B) Always inverted
C) Always erect                                         D) None of the above

46. Where should an object be placed from a converging lens of focal length 10 cm. So, as to obtain a virtual image of magnification 2 is
A) 5 cm             B) 10 cm              C) 20 cm            D) None of the above

47. An object is placed 16 cm from a convex lens of focal length 8 cm. The image must be
A) virtual and enlarge                     B) real and diminished
C) real and enlarged                         D) real and same size

48. An object of height 2 cm is placed infront of a concave lens of focal length 15 cm at a distance of 45 cm. The height of the image formed by the lens is
A) 1 cm              B) 2 cm               C) 4 cm                 D) 5 cm

49. Two plano convex lenses of focal lengths 10 cm and 20 cm are placed in contact with each other. The effective focal length of the combination is
A) 3.52 cm         B) 6.66 cm         C) 13.22 cm          D) 37.44 cm

50. An object is placed infront of convex lens of focal length 15 cm. At what distance the object must be placed, so that the image is also formed at the same distance on the other side of the lens
A) 15 cm            B) 20 cm             C) 25 cm                 D) 30 cm

51. A Biconvex lens of focal length 20 cm is cut along a plane perpendicular to principal axis so as to make two plano convex lenses. The focal length of each plano convex lens is .........                                                                                                                                        ( )
A) 10 cm              B) 20 cm            C) 40 cm                D) 60 cm

52. If the focal length is positive then the lens is
A) convex          B) concave        C) plano concave           D) None of these

53. If the focal length is negative then the lens is..............
A) Convex           B) Concave            C) Plano convex            D) None of above

54. The heights measured vertically down from points on axis are taken as.......
A) positive          B) negative            C) inverted                    D) erected

55. Distance measured opposite to the direction of the incident light ray are taken as ...............
A) positive           B) negative            C) no sign                    D) any size

56. The virtual image formed with a convex lens when the object is placed.....
A) at F               B) at C                     C) beyond C                 D) between P and F

57. Which of the following is true?
A) The distance of virtual image is not greater than the object distance for convex lens.
B) Convex lens always forms a real image.
C) Convex lens always forms a virtual image.
D) The distance of virtual image is always greater than the object distance for convex lens.

58. If the size of image is larger, then it is called ........ image.
A) Magnified            B) Inverted             C) Diminished               D) Erected

59. A real inverted and enlarged image is formed by a convex lens when the object is placed.....
A) at F                         B) at 2F                  C) between F and 2F      D) beyond 2F

60. The image formed by a concave lens is .....
A) real       B) virtual and enlarge    C) always virtual and diminished      D) None

61. A real image formed by a convex lens is always......
A) erect                                     B) inverted
C) smaller than the object        D) on the same side of the lens as the object

62. The image formed by a convex lens is virtual, erect and larger than the object. The position of the object must be

A) at F                                             B) at C
C) between F and C                         D) between P and F

63. When a news paper is seen through a lens, its print appears smaller. The nature of the lens is
A) convex               B) concave           C) concavo - convex        d) none of these

64. Aconcave lens of focal length 15 cm forms an image at a distance of 10 cm from the lens. The distance of the object from lens is
A) +45 cm            B) +30 cm               C) -30 cm              D) -45 cm

65. An object is placed at a distance of 10 cm from a convex lens of focal length 15 cm. The position of image is
A) -10 cm            B) +15 cm               C) +30 cm              D) -30 cm

66. A Convex lens produces a real and magnified image when an object is 10 cm from the lens and the image is formed at 30 cm. The focal length of lens is
A) 1.5 cm            B) 7.25 cm               C) 10 cm                 D) 14.5 cm

67. If a magnification of -1 is to be obtained by using a converging lens of focal length 8 cm, then the object must be placed
A) 8 cm              B) 12 cm                   C) 16 cm                 D) 24 cm

68. In the follwing figure F1 shows A) center of concave lens                    B) center of convex lens
C) focus of concave lens                     D) focus of convex lens

69. In the follwing figure F1 shows A) center of concave lens                  B) centre of convex lens
C) focus of concave lens                   D) focus of convex lens

70. Which of the following ray diagram is not correct. 71. Which of the following ray diagram is correct. 72. Which of the following ray diagram is not correct. Answers: 1-B;  2-A;  3-D;  4-D;  5-A; 6-B;  7-C;  8-B;  9-C;  10-D; 11-C;  12-D; 13-D; 14-B;  15-C;  16-C; 17-A;  18-D;  19-C; 20-D;  21-C; 22-C; 23-D;  24-C;  25-B; 26-B;  27-B;  28-C;  29-A;  30-D;  31-C; 32-C;  33-C;  34-C;  35-B;  36-A; 37-B; 38-A;  39-C;  40-A; 41-B; 42-C; 43-D;  44-C;  45-C;  46-A; 47-D; 48-A;  49-B;  50-D; 51-C;  52-A; 53-B;  54-B;  55-B;  56-D;  57-A; 58-A;  59-C;  60-C;  61-D; 62-D; 63-B;  64-C;  65-D;  66-B;  67-C; 68-D;  69-C; 70-D;  71-D; 72-D.

Posted Date : 07-10-2020

గమనిక : ప్రతిభ.ఈనాడు.నెట్‌లో కనిపించే వ్యాపార ప్రకటనలు వివిధ దేశాల్లోని వ్యాపారులు, సంస్థల నుంచి వస్తాయి. మరి కొన్ని ప్రకటనలు పాఠకుల అభిరుచి మేరకు కృత్రిమ మేధస్సు సాంకేతికత సాయంతో ప్రదర్శితమవుతుంటాయి. ఆ ప్రకటనల్లోని ఉత్పత్తులను లేదా సేవలను పాఠకులు స్వయంగా విచారించుకొని, జాగ్రత్తగా పరిశీలించి కొనుక్కోవాలి లేదా వినియోగించుకోవాలి. వాటి నాణ్యత లేదా లోపాలతో ఈనాడు యాజమాన్యానికి ఎలాంటి సంబంధం లేదు. ఈ విషయంలో ఉత్తర ప్రత్యుత్తరాలకు, ఈ-మెయిల్స్ కి, ఇంకా ఇతర రూపాల్లో సమాచార మార్పిడికి తావు లేదు. ఫిర్యాదులు స్వీకరించడం కుదరదు. పాఠకులు గమనించి, సహకరించాలని మనవి.