1Reflection of Light 1. If an object is placed unsymmetrical between two plane mirrors, inclined at an angle of 72 0 , then the total number of images formed is (a) 5 (b) 4 (c) 2 (d) infinite 2. If an object is placed symmetrically between two planemirrors , inclined at an angle of 72 0 , then the total number of mirages formed is (a) 5 (b) 4 (c) 2 (d) infinite 3. The number of images observable between two parallel mirrors is (a) 2 (b) 4 (c) 6 (d) infinite 4. A light bulb is placed between tow plane mirrors inclined at an angle of 60 0 . The number of images formed are (a) 6 (b) 2 (c) 5 (d) 4 5. An object 5 cm long and a pencil 10 cm long are placed in front of a pin hole camera such that their images have the same length. The ratio of the distance of object from the pin hole of that of the pencil is (a) 3:2 (b) 1:2 (c) 5:2 (d) 1:4 6. A plane mirror is approaching you at 10 cm per second .You can see your images in it. At what speed will your image approach you (a) 10 cm/sec (b) 5 cm/sec (c) 20 cm/sec (d) 10 cm/sec 7. It is desired to photograph the images of an object placed at a distance of 3 cmfroma plan mirror . The camera, which is at a distance of 4.5 m from the mirror should be focused for a distance of (a) 3 m (b) 4.5 cm (c) 6 m (d) 7.5 m 8. A man 180 cm high stands in front if a plane mirror . His eyes are at a height of 170 cmfromthe floor. Then the minimum length of plane mirror for him to see his full length images is (a) 90 cm (b) 180 cm (c) 45 cm (d) 360 cm 9. In question no.8 lower edge of the mirror should be above the ground at a height of (a) 85 cm (b) 170 cm (c) 45 cm (d) 90 cm 10. How many images of himself does an observer see if two adjacent walls and the ceiling of a rectangular roomare mirror surfaced (a) 3 (b) 5 (c) 7 (d) 9 11. A convex lens of focal length 20 cm is placed in front of a convex mirror of radius of curvature 15 cm . A luminous object is placed in front of the convex lens at a distance of 40 cm from it. Then the distance between the convex mirror and the convex lens to get an inverted (a) 40 cm (b) 25cm (c) 15cm (d) 35cm 12. In question no.11 , the distance between the convex mirror and the convex lens to get an upright images of the luminous object coincident with the object , is (a) 40 cm (b) 90cm (c) 15cm (d) 35cm 2 13. The image formed by convex mirror of focal length 30 cmis a quarter of thesize of the object . Then the distance of the object fromthe mirror, is (a) 30 cm (b) 90 cm (c) 120 cm (d) 60 cm 14. A concave mirror of focal length 100 cm is used to obtain theimage of the sun which subtends an angle of 30, then the diameter of the image of the sun, is (a) 1.74 cm (b) 0.87 cm (c) 0.453 cm (d) 100 cm 15. A convex mirror of focal length f produces an image n times thesize of the object. if the image is real then the distance of the object from the mirror , is (a) (n-1)f (b) f n 1 n | . | \ | ÷ 4 (c) f n 1 n | . | \ | + (d) (n+1)f 16. A convex mirror of focal length f produces an image 2 1 the of the size of the object. The distance of the object fromthe mirror, is (a) (n-1)f (b) f n 1 n | . | \ | ÷ 4 (c) f n 1 n | . | \ | + (d) (n +1)f 17. A convex mirror has f focal length f. A real object is placed at a distance f in front of it from the pole , produced an image at (a) infinity (b) f (c) 2 f (d) 2f 18. In a concave mirror an object is placed at a distance x 1 from the focus , and the image is formed at a distance x 2 from the focus, Then the focal length of the mirror is (a) x 1 x 2 (b) 2 1 x x (c) 2 x x 2 1 + (d) 2 1 x x 19. The figure shows two rays A and B being reflected by a mirror and going as A’ and B. The mirror is (a) plane (b) concave (c) convex (d) may be any spherical mirror 20. A clock hung on a wall has marks instead of numbers on its dial. On theopposite wall there is a mirror, and the imageof the clock in the mirror if read, indicates the times as 8.20. What is the time in the clock? (a) 3.40 (b) 4.40 (c) 5.20 (d) 4.20 21. The focal length of a concave mirror is 12 cm. Where should an object of length 4 cm be placed so that an images 1 cmlong is formed ? (a) 48 cm (b) 3 cm (c) 60 cm (d) 15cm 22. The sun subs tends an angle 30’ on the surface on the earth. What would be the diameter of the image of the sun formed by a concavemirror whose radius of curvature is 60 cm? (a) 30 cm (b) 0.13cm (c) 0.26cm (d) 0.52 cm 23. The focal length of a concave mirror is f and the distance from the object to the principal focus is x. A B A’ B’ 3 Then the ratio of the size of the imageto the sizeof the object is (a) f ) x f ( + (b) x f (c) x f (d) 2 2 x f . 24. A pinhole camera is used to photograph the sun which subtends an angle 30’. If the screen is 100 cm from the pin hole , the diameter of the image of the sun is (a) 50 cm (b) 0.435 cm (c) 1.74cm (d) 0.87cm 25. A small hole is madein the window shutter of a 5 m wide room when a 1 m high images of a tree 30 mfromthe window is cast on the oppositewall. The actual height of the tree is (a) 3m (b) 6m (c) 12m (d) 150 m 26. The focal length of a concave mirror is 20 cm. Determine where an object must be placed to form an image magnitudetwo times when the images is real (a) 30 cmfromthe mirror (b) 10 cmfromthe mirror (c) 20 cmfromthe mirror (d) 15 cmfromthe mirror 27. In the above question , if the magnified image is virtual, the distance of the object from the mirror must be (a) 30 cm (b) 10 cm (c) 20 cm (d) 15 cm 28. When a convergent beamof light is incident on a planemirror, the formed is (a) upright and real (b) upright and virtual (c) inverted and virtual (d) inverted and real 29. A thick plane mirror shows a number of images of the filament of an electric bulb . Of these , the brightest imageis the (a) first (b) second (c) last (d) fourth 30. A ray of light incident on a plane mirror at an angle of incidence of 30’. The deviation produced by the mirror is (a) 30 0 (b) 60 0 (c) 90 0 (d) 120 0 31. A virtual image , large than the object can be produced by (a) convex mirror (b) concave mirror (c) plane mirror (d) concave lens 32. Given a point source of light , which of the following can produce a parallel beamof light (a) convex mirror (b) concave mirror (c) concave lens (d) two plane mirror inclined at 90 0 to each other 33. The picture seen on the screen of a pinhole camera is (a) an image (b) a shadow (c) neither an image nor a shadow (d) both an image and a shadow 34. A plane mirror reflection a ray of incident light is rotated through an angle u about an axis through the point of incidence in the plane of the mirror perpendicular to theplane of incidence then (a) the reflected ray does not rotate (b) the reflected ray rotates through angle u (c) the reflected ray rotates through an angle 2u (d) the incident ray is fixed 35. A convex mirror is used to form an images of a real object . Then tick the wrong statement (a) the image lies between the pole and the focus (b) the image is diminished in size (c) the image is erect (d) the image is real 4 36. Sunlight filtering through a tree often makes circular patches on the ground because (a) the space through which light penetrates is round (b) the sun is round (c) light is transmitted as wave motion (d) due to diffraction phenomenon 37. light (a) travels strictly straight line (b) travels approximately in straight line (c) in a wavy form (d) travels with infinitevelocity 38. A virtual object placed between the pole and the principal focus of a convex mirror produces an image which is (a) real, magnified and upright (b) virtual , diminished and inverted (c) virtual , diminished and upright (d) real, diminished and inverted ] 39. The field of view is maximum for (a) Plane mirror (b) concave mirror (c) convex mirror (d) cylindrical mirror 40. A disc is placed with its one edge parallel to the principal axis between the principal focus and the centre of the curvature of a concave mirror, Then the images has the shape of (a) cube (b) cuboid (c) barrel shaped (d) spherical 41. A person standing in front of a mirror finds his image larger then himself. This implies that the mirror is (a) plane (b) convex (c) concave (d) cylindrical with building side outwards 43. A person standing in front of a mirror finding image thinner but with normal height . This implies that the mirror is (a) convex and spherical (b) concave and spherical (c) convex and cylindrical with axis vertical (d) convex and cylindrical with axis horizontal 44. A diminished virtual image can beobtained only in (a) a plane mirror (b) a convex spherical mirror (c) a convex spherical mirror (d) a concave parabolic mirror 45. A bird flying high up in the air does not cast a shadow on the ground because (a) size of bird is smaller then sun (b) layers of atmosphere are dense (c) the light rays are not falling on it (d) none of these 46. Which of the following could not produce a virtual image ? (a) plane mirror (b) convex mirror (c) convex lens (d) concave mirror (e) all of the above can produce a virtual image 47. The mirror is an ordinary glass mirror and the boy looks carefully . Hesees a second faint imagein top of the main brighter image . This ghost images is dueto (a) the flickering of the candle flame (b) the mirror not being quite flat (c) reflection fromthe front of the mirror (d) reflection in the air caused by the heat of the flame 48. A man stands in the centre of a room. A plane mirror is fixed on the wall in front of him. What should be the smallest length of the mirror so that he may seetheimage of the whole of theback wall (a) half the height of the wall (b) one third the height of thewall (c) one fourth theheight of the wall (d) one fifth the height of the wall 49. The larger distance of the image from a convex mirror of focal length 10 cmcan be (a) 20 cm (b) infinite (c) 10 cm (d) depends on theposition of the object 50. Indicate the only correct statement in the following (a) the virtual image formed in a plane mirror can be photographed (b) given a point source of light, a convex mirror can produce a parallel beamof light (c) concave mirror can give diminished virtual image (d) an object situated at the principal focus of a concave lens will haveits images formed at infinity 5 51. In a pinhole camera, the effect of doubling the diameter of the hole from0.5 mmto 1.0 mmis (a) double the magnification of the image (b) worsen the chromatic aberration of theimage (c) increase the blurring of the image caused by diffraction (d) cut thenecessary exposuretime to onefourth its previous value. 52. The reflected successively from two plane mirrors inclined at a certain angle undergoes a deviation of 300 0 . Then the number of images observable is (a) 60 (b) 12 (c) 11 (d) 5 53. A plane mirror reflects a pencil of light to forma real image. Then the pencil of light incident on the mirror is (a) parallel (b) convergent (c) divergent (d) any one of the above types 54. When a plane mirror is placed horizontally on level ground at a distance of 60 metres fromthe foot of a tower, the top of the tower and its images in the mirror subtend at theeye an angle of 90 0 . The height of the tower is (a) parallel (b) convergent (c) divergent (d) any one of the above types 55. When a planemirror is placed horizontally on level ground at a distance of 60 meters fromthe foot of a tower , the top of the tower and its image in the mirror subtend at theeye an angle of 90 0 . The height of the tower is3 (a) 30 m (b) 60 m (c) 90 m (d) 120 m 56. A ray of light makes an angle of 10 0 with the horizontal and strikes a plane mirror which is inclined at an angle u to the horizontal . The angle u for which the reflected ray becomes vertical , is (a) 40 0 (b) 50 0 m (c) 80 0 m (d) 100 0 m 57. A driving mirror consists of a cylindrical mirror of radius 10 cm and the length over thecurved surface of 10 cm. If the eye of the driven be assumed to be at a great distance from the mirror , then the field of view in radians , is (a) 0.5 (b) 1.0 (c) 2.0 (d) inderminate 58. A concave mirror of radius of curvature 60 cm is placed at the bottomof a tank containing water upto a height of 20 cm. The mirror faces upwards with its axis vertical . Solar light falls normally on the surfaceof water and the image of the sun is formed. If a µ w= 3 4 then with the observer in air, the distance of the image fromthe surface of water is (a) 30 cm (b) 10 cm (c) 7.5cmabove (d) 7.5 cmbelow 59. A man 2 meters tall stands 5 metres in front of a large vertical plane mirror. Then the angle subtended at his eye by his image in the plane mirror is (a) 0.4 radian (b) 0.2 radian (c) 0.2 degree (d) 0.4 degree 60. Two plane mirrors are inclined to each other at an angleu. If a ray of light incident on thefirst mirror parallel to the second mirror parallel to the first mirror, then the angle u is (a) 30 0 (b) 60 0 (c) 120 0 (d) 90 0 61. Rays of light strike a horizontal plane mirror at an angleof 45 0 A second plane mirror is arranged at an angle u with it. If the ray after reflection fromthe second mirror runs horizontally i.e., parallel to the first mirror, then u is (a) 45 0 (b) 60 0 (c) 67 0 30’ (d) 135 0 62. Two vertical plane mirrors are inclined at an angle of 60 0 with each other . A ray of light travelling horizontally is reflected first from one mirror and 6 then form the other mirror. Then the resultant deviation is (a) 60 0 (b) 120 0 (c) 180 0 (d) 240 0 63. Theimage formed by a concavemirror is (a) always real (b) always virtual (c) is certainly real if the object is virtual (d) is certainly virtual if the object is real 64. A luminous object is placed 20 cmfromthe surface of a convex mirror and a planemirror is set so that the virtual images formed in the two mirrors coincide. If the plane mirror is at a distance of 15 cm fromthe object , then the focal length of the convex mirror, is (a) 10 cm (b) 15 cm (c) 20 cm (d) 40 cm 65. A concave mirror forms an image of the sun at a distance of 12 cmfromit. (a) the radius of curvature of this mirror is 6cm (b) to useit as a shaving mirror, it ,must beheld at a distance of 8-10 cmfromthe face (c) if an object is kept at a distance of 12 cm from it, the imageformed will be of thesame size as the object (d) all the above alternative are correct 66. The rectilinear propagation of light in a mediumis dueto (a) its large wavelength (b) its high frequency (c) largevelocity (d) refractiveindex of the medium 67. A concave mirror is used to forman image of the sun on a white screen. If the lower half of the mirror ware covered with an opaque card, the effect on the image on the screen would be (a) negligible (b) to make the image less bright than before (c) to make the upper half of the image disappear (d) to make the lower half of the image disappear 68. The hole in a pinholecamera is made very small in order that the imageformed is (a) real and magnified (b) real and diminished (c) virtual and diminished (d) sharp 69. Which one of the following statements is correct for spherical mirrors ? (a) a concave mirror forms only virtual images for any position of the object (b) a concave mirror forms only virtual images for any position of the object (c) a concave mirror forms only a virtual diminished image of an object placed between its pole and the focus. (d) a convex is looking forms a virtual magnified image of an object placed between its pole and the focus 70. A person is looking at the image of his face in a mirror by holding it close to his face. The image is virtual. When he moves the mirror away from his face, the image is inverted. What type of mirror is he using (a) plane mirror (b) concave mirror (c) convex mirror (d) none of these 71. We cannot see the shadow of a bird flying high in the air because (a) the shadow changes its position very quickly as the bird flies (b) the umbra of the image becomes very large and faint (c) the umbra and penumbra overlap (d) the umbra vanishes altogether and the penumbra becomes too faint to be observed 72. An object 3 cm tall is placed on theprincipal axis of a concave mirror of focal length 9 cm at a distance of 12 cm from it. What is the nature and size of the image? (a) real, 9 cm (b) virtual, 9 cm (c) real,1 cm (d) virtual 1cm 73. An object 5 cm tall is placed is placed 10 cm principal axis of a concave mirror of focal length 9 cm at a distance of 12 cmformit. What is the nature and sizeof theimage (a) real, 3 cm (b) virtual, 9 cm (c) virtual 3 cm (d) real, 7.5 cm 74. Thefocal length of a plane mirror is (a) zero (b) infinite 7 1/v 1/u O 1/v 1/u O 1/v 1/u O A B x ’ X 1 2 3 4 1/v 1/u O (c) finite but negative (d) finite but positive 75. On rotating a plane mirror, the reflected ray (a) shows no rotation (b) rotates through an anglewhich is twice that of the mirror (c) rotates through an angle which is equal to that of the mirror (d) rotates towards the incident ray 76. A concave mirror of radius of curvature 30 cm forms an images 2.5 cmhigh of an object 1 cmhigh placed on its principal axis. The image (a) must be a real image (b) must be a virtual image (c) may be a real or a virtual image (d) nothing can be said definitely 77. An object is placed at a distance u cm form a concave mirror of focal length f cm. The real image of the object is received on a screen placed at a distance of v cmformthe mirror. The values of u are changed and the corresponding values of v are measured. Which one of the graphs shown in the figure represents the variation of u 1 with v 1 (a) (b) (c) (d) 78. What is the value of 0 u 1 when v 1 = in the correct graph of Q . 77 above? (a) f (b) f (c) f 2 (d) f 1 79. A short linear object of length l lies along the axis of a concave mirror of focal length f at a distance u form the pole of the mirror . The size of the image is approximately equal to (a) 2 1 f f u l | . | \ | ÷ (b) 2 f f u | . | \ | ÷ (c) 2 1 f u f l | . | \ | ÷ (d) 2 f u f l | . | \ | ÷ 81. For a real object, a convex mirror always forms an image which is (a) real and inverted (b) virtual and inverted (c) virtual and erect (d) real and magnified 82. A ray of light travels fromA to B with a uniform speed . On its way it is reflected by the surface XX’. The path followed by the ray to takeleast time is (a) 1 (b) 2 (c) 3 (d) 4 83. Ray optics is valid, when charateristic dimensions are (a) of the same order as the wavelength of light (b) much smaller than the wavelength of light (c) of theorder of onemillimeter (d) much larger than the wavelength of light 84. A man sees his faceenlarged in a mirror. The mirror is (a) plane (b) convex (c) concave (d) cylindrical 85. Two plane mirrors are at right angles to each other . A man stands between them and combs his hair with 8 mm 10 mm M1 M2 2 O his right hand. In how may of the images will he be seem using his right hand ? (a) none (b) 1 (c) 2 (d) 3 86. If an object is placed 10 cmin front of a concave mirror or focal length 20 cm, the image will be (a) diminished , upright , virtual (b) enlarged , upright virtual (c) enlarged , upright , real (d) enlarged , upright, real 87. Reflectors used in solar cookers are (a) convex (b) concave (c) plane (d) cylindrical 88. A light ray incident normally on a plane mirror suffers a deviation of (a) 0 0 (b) 2 t (c) t (d) 2t 89 A dentist has a small mirror of focal length 16 mm . He views the cavity in the tooth of a patient by holding the mirror at a distance of 8 mformthe cavity . Themagnification is (a) 1 (b) 1.5 (c) 2 (d) 3 90. With a fixed incident ray, if a plane mirror is rotated through an angle u about an axis lying perpendicular to its plane, then the reflected ray turns through an angle (a) zero degree (b) 2u (c) u/2 (d) 3u 91. A small piece of wire bent into an L shape with upright and horizontal portions of equal lengths , is placed with the horizontal portion along the axis of the concave mirror whose along the axis of the concavemirror whose radius of curvature is 10 cm. If the bend is 20 cm from the pole of the mirror, then the ratio of the lengths of the images of the upright and horizontal portion of the wire is (a) 1:2 (b) 3:1 (c) 1:3 (d) 2:1 92. A concavemirror forms , on a screen a real image of twice the linear dimensions of the object . Object and screen are then moved until theimage is three times the size of the object. If the shift of the screen is 25 cm, then the focal length of the mirror is (a) 5 cm (b) 16.60 cm (c) 25 cm (d) 37.5 cm 93. A point object O is placed between two plane mirrors as shown in Fig . The distance of the first three images formed by mirror M 2 fromit are 94. A cubical roomis formed with six plane mirrors. An insert moves along the diagonal of the floor with uniformspeed . The velocities of its image in two adjacent walls are 20 2 cm/sec, then the velocity of the image formed by the roof , is (a) 20 cm/sec (b) 40 cm/sec (c) 20 2cm/sec (d) 10 2 cm/sec 95. A convex mirror of focal length 10 cmforms an image which is half of the size of the object . The distance of the object formthe mirror is (a) 10 cm (b) 20 cm (c) 5 cm (d) 15 cm 96. The image of an extended object, placed perpendicular to the principal axis of a mirror , will be erect if (a) the object and theimage are both real (b) the object and theimage are both virtual (c) the object is real but the image is virtual (d) the object is virtual but the image is real 97. In image formation from spherical mirrors, only paraxial rays are considered because they 9 (a) are easy to handle geometrically (b) contain most of the intensity of the incident light (c) the object is real but the image is virtual (d) show minimumdispersion effect 98. At what angle must two plane mirrors be placed so that the incident and resulting reflected rays are always parallel to each other (a) 0 0 (b) 30 0 (c) 60 0 (d) 90 0 99. A boy stands straight in front of a mirror at a distance of 30 cm away from it. He sees his erect image whose height is 1/5 th of his real height . The mirror he is using (a) plane mirror (b) convex mirror (c) concave mirror (d) plane – concave mirror 100. The image formed by a convex mirror of real object is larger then the object (a) when u is less than 2f (b) when u is more than 2f (c) for all value of u (d) for no value of u 101. Two plane mirrors are parallel to each other and spaced 20 cm apart . An object is kept in between then at 15 cm a from A . Out of the following at which point an image is NOT formed in mirror A (distance measured frommirror A) (a) 15 cm (b) 25 cm (c) 45 cm (d) 55 cm 102. A convergent beamof light converges to a point 20 cm behind the convex mirror on the principal axis. An inverted images of the same size is formed coincident with the virtual object . Then the focal length of the convex mirror is (a) 20cm (b) 10 cm (c) 40cm (d) 15 cm 103. Number of images of an object kept unsymmetrical between two plane mirror inclined at angle 72 0 , would be (a) two (b) three (c) six (d) five 104. A point object is placed mid-way between two plane mirrors distance ‘a’ apart. The plane mirror forms an infinite number of images dueto multiple reflection . The distance between the nth order image formed in the two mirrors is (a) na (b) 2na (c) na/2 (d) n 2 a 105. A concave mirror is placed on a horizontal table with its axis directed vertically upwards . Let O be the pole of the mirror and C its centre of curvature . A point object is placed at C. If the mirror is now filled with water, theimage will be (a) real and will remains at C (b) real and located at a point between C and · (c) virtual and located at a point between C and O (d) real and located at a point between C and O 10 Answer s 1. (a) 2. (b) 3. (d) 4. (c) 5. (b) 6. (c) 7. (d) 8. (a) 9. (a) 10. (c) 11. (b) 12. (a) 13. (b) 14. (b) 15. (c) 16. (a) 17. (c) 18. (b) 19. (a) 20. (a) 21. (c) 22. (c) 23. (b) 24. (d) 25. (c) 26. (a) 27. (b) 28. (a) 29. (b) 30. (d) 31. (b) 32. (b) 33. (c) 34. (c) 35. (d) 36. (c) 37. (b) 38. (A) 39. (c) 40. (b) 41. (b) 42. (c) 43. (c) 44. (c) 45. (a) 46. (e) 47. (c) 48. (b) 49. (c) 50. (a) 51. (d) 52. (a) 53. (c) 54. (b) 55. (b) 56. (a,b) 57. (c) 58. (c) 59. (b) 60. (b) 61. (c) 62. (d) 63. (c) 64. (c) 65. (c) 66. (b) 67. (b) 68. (d) 69. (b) 70. (b) 71. (d) 72. (a) 73. (c) 74. (b) 75. (b) 76. (c) 77. (c) 78. (d) 79. (a) 80. (d) 81. (c) 82. (c) 83. (d) 84. (c) 85. (b) 86. (b) 87. (b) 88. (b) 89. (c) 90. (a) 91. (b) 92. (c) 93. (c) 94. (b) 95. (a) 96. (c,d) 97. (c) 98. (d) 99. (b) 100. (d) 101. (c) 102. (b) 103. (d) 104. (b) 105. (d)