Light — Reflection and Refraction · Class 10 Science: 264 MCQs with answers

Q1. The angle of incidence is the angle between the incident ray and the:

Q2. According to the first law of reflection:

Q3. You stand 3 m in front of a plane mirror. Your image is formed:

Q4. Lateral inversion means the interchange of:

Q5. The line perpendicular to a reflecting surface at the point of incidence is called the:

Q6. We can see a book lying on a table from any direction because the book's surface shows:

Q7. The size of the image formed by a plane mirror is:

Q8. A ray of light falls on a plane mirror along its normal. The angle of reflection is:

Q9. Which of these is a luminous object?

Q10. The second law of reflection says the incident ray, reflected ray and normal:

Q11. An image that CAN be obtained on a screen is called:

Q12. State the two laws of reflection of light.

Q13. What is lateral inversion? Give one everyday consequence of it.

Q14. An object is placed 12 cm in front of a plane mirror. Where is the image, and what is the distance between object and image?

Q15. A ray of light is incident along the normal to a plane mirror. What are the angle of incidence and the angle of reflection?

Q16. A steel spoon is held with its HOLLOW side facing you, close to your face. Your face looks enlarged and the right way up. The hollow side is behaving as:

Q17. Two concave mirrors have focal lengths 9 cm and 18 cm. Their radii of curvature are, respectively:

Q18. A concave mirror gives a virtual, erect and magnified image when the object is:

Q19. Define principal focus of a concave mirror.

Q20. Define principal focus of a convex mirror.

Q21. Give two uses each of concave and convex mirrors, with the reason for each.

Q22. Which mirror always gives a diminished, erect image? What advantage does this give in vehicles?

Q23. In the New Cartesian sign convention, all distances are measured from the:

Q24. The object distance u for a mirror is always:

Q25. The focal length of a concave mirror is taken as:

Q26. The focal length of a convex mirror is taken as:

Q27. The mirror formula is:

Q28. Magnification of a mirror equals:

Q29. A magnification of −1 means the image is:

Q30. A positive magnification means the image is:

Q31. Heights measured above the principal axis are taken as:

Q32. State the three rules of the New Cartesian sign convention.

Q33. The magnification produced by a mirror is +1. What does this tell you about the mirror and the image?

Q34. Light travelling from a rarer to a denser medium bends:

Q35. Light travelling from glass to air bends:

Q36. A ray incident normally (i = 0°) on a glass slab:

Q37. sin i / sin r = constant is known as:

Q38. The absolute refractive index of a medium equals:

Q39. Which of these has the highest refractive index?

Q40. Light travels slowest in:

Q41. The emergent ray from a rectangular glass slab is:

Q42. A coin in a water-filled bucket appears raised because of:

Q43. Which of these statements about the image in a plane mirror are correct? I. It is virtual and erect. II. It is the same size as the object. III. It is laterally inverted. IV. It lies as far behind the mirror as the object stands in front. Which statements are correct?

Q44. A plane-mirror image cannot be caught on a screen because:

Q45. Which group lists ONLY non-luminous objects?

Q46. A ray strikes a plane mirror at 30° to the mirror SURFACE. The angle of incidence is:

Q47. A ray strikes a plane mirror with an angle of incidence of 35°. The angle between the incident ray and the reflected ray is:

Q48. The angle between an incident ray and the mirror surface is 25°. The angle of reflection is:

Q49. A man stands 4 m from a plane mirror and his friend stands 6 m from the same mirror beside him. How far is the man from his FRIEND'S image?

Q50. You walk towards a plane mirror at 2 m/s. Your image approaches YOU at:

Q51. The angle between the incident ray and the reflected ray is 90°. The angle of incidence is:

Q52. A plane mirror is rotated by 10° keeping the incident ray fixed. The reflected ray rotates by:

Q53. Which letter of the alphabet would appear UNCHANGED in a plane mirror?

Q54. A clock shows 4:00. In a plane mirror, it will appear to show:

Q55. Diffuse reflection occurs because on a rough surface:

Q56. In a periscope, the two plane mirrors are inclined to the tube's axis at:

Q57. The final image seen through a periscope is:

Q58. Two plane mirrors are placed at 90° to each other. The number of images of an object between them is:

Q59. Two plane mirrors face each other, parallel. The number of images formed is:

Q60. A ray reflected from a plane mirror retraces its path. The angle of incidence was:

Q61. An object moves 30 cm closer to a plane mirror. The distance between the object and its image decreases by:

Q62. Why can a virtual image not be obtained on a screen?

Q63. A ray of light strikes a plane mirror such that the angle between the incident ray and the reflected ray is 60°. Find the angle of incidence.

Q64. Distinguish between regular and diffuse reflection. Do the laws of reflection hold in diffuse reflection?

Q65. With the help of a labelled description, explain how the image of an object is formed by a plane mirror, and state all the characteristics of this image.

Q66. A ray aimed at the centre of curvature of a concave mirror comes straight back along its own path because it:

Q67. Two rays leave the tip of an object in front of a concave mirror — one parallel to the axis, the other through F. After reflection the two rays:

Q68. A shopkeeper fixes a convex mirror high in a corner of the shop. The single property that makes it useful there is that it:

Q69. Which of these images could actually be caught on a screen?

Q70. The bulb of a torch sits at the focus of its concave reflector so that the light:

Q71. A dentist holds a small concave mirror very close to a tooth — nearer than its focus. The image seen is:

Q72. Parallel rays from a distant tower fall on a concave mirror of focal length 25 cm. A screen catches a sharp image at:

Q73. An object is at C of a concave mirror. The image is:

Q74. An object is placed between C and F of a concave mirror. The image is:

Q75. To get a real image of the SAME size, the object in front of a concave mirror must be at:

Q76. To burn a paper using a concave mirror and sunlight, the paper must be held at:

Q77. The image formed by a convex mirror lies:

Q78. An object moves from infinity towards the focus of a concave mirror. Its real image:

Q79. Rule 4: a ray incident AT the pole of a concave mirror reflects:

Q80. Which single mirror can show BOTH a magnified and a diminished image (at different object distances)?

Q81. Street lights use convex reflecting surfaces because they:

Q82. A student sees her erect image become inverted as she slowly moves AWAY from a mirror. The mirror is:

Q83. A convex mirror is called a DIVERGING mirror because it:

Q84. Assertion (A): A concave mirror is used in a solar cooker. Reason (R): A concave mirror is also used as a shaving mirror and by dentists to examine teeth.

Q85. Four concave mirrors have radii of curvature 10 cm, 20 cm, 30 cm and 40 cm. Sunlight converges NEAREST the pole for the mirror of radius:

Q86. A concave mirror forms a sharp image of the Sun 8 cm from its pole. Its radius of curvature is:

Q87. Which group lists ONLY uses of a CONCAVE mirror?

Q88. The focal length of a concave mirror is 12 cm. Where must an object be placed to get (a) a real, same-size image, (b) a virtual, magnified image?

Q89. Why does a ray of light passing through the centre of curvature of a concave mirror retrace its path?

Q90. An object is placed at the focus of a concave mirror. Describe the image.

Q91. The image of a candle flame formed by a concave mirror is caught sharply on a screen. What TWO properties of the image can you state immediately?

Q92. How would you quickly find the approximate focal length of a concave mirror on a sunny day?

Q93. With the six standard cases, describe image formation by a concave mirror as an object is moved from infinity to the pole, and connect each case to one practical use where possible.

Q94. Describe an activity to distinguish a plane mirror, a concave mirror and a convex mirror WITHOUT touching their surfaces.

Q95. For a real image formed by a mirror, the image distance v is:

Q96. An object is 30 cm in front of a concave mirror with f = 15 cm. The image distance is:

Q97. For the same case (u = −30, f = −15), the magnification is:

Q98. An object is 20 cm in front of a convex mirror with f = +10 cm. The image forms:

Q99. An object placed at the focus of a concave mirror gives 1/v = 0. This means the image is at:

Q100. A mirror produces m = +1/2 for all reasonable object positions. The mirror is:

Q101. A concave mirror forms a real image 3 times the object's size. The magnification is:

Q102. If m = −0.5 for a mirror, the object lies:

Q103. Assertion (A): For a convex mirror the image distance v is always positive. Reason (R): A convex mirror always forms its image behind the mirror.

Q104. A student writes u = +25 cm for an object standing in front of a mirror. The mistake is that:

Q105. Why is the focal length of a concave mirror negative but that of a convex mirror positive?

Q106. An object is placed 24 cm in front of a concave mirror of focal length 16 cm. Find the position of the image.

Q107. For the numerical above (u = −24, v = −48), find the magnification and describe the image fully.

Q108. A convex mirror of focal length 20 cm forms an image of an object placed 30 cm away. Find v and m.

Q109. Refraction happens at the boundary between two media because:

Q110. If the speed of light in a medium is 1.5 × 10⁸ m/s, its refractive index is:

Q111. The refractive index of glass is 1.5. The speed of light in glass is:

Q112. n(water) = 1.33 and n(glass) = 1.52. Light going from glass INTO water bends:

Q113. The refractive index of water with respect to glass (n glass→water) equals:

Q114. In the glass-slab experiment, the angle of emergence is:

Q115. Lateral displacement does NOT depend on:

Q116. Which quantity is unchanged when light enters glass from air?

Q117. Kerosene (n = 1.44) floats on water (n = 1.33). Which statement is TRUE?

Q118. n₂₁ = 4/3 for water w.r.t. air. Then n₁₂ (air w.r.t. water) is:

Q119. Light travels at 2.25 × 10⁸ m/s in water. Taking c = 3 × 10⁸ m/s, the refractive index of water is:

Q120. Four media P, Q, R and S have refractive indices 1.31, 1.44, 1.50 and 2.42. A ray entering from air bends MOST on entering:

Q121. The refractive index of a medium is 1.6. The speed of light inside it is about:

Q122. The refractive index of glass with respect to air is 1.5. The refractive index of air with respect to glass is:

Q123. Which group lists ONLY effects of REFRACTION?

Q124. A ray bends AWAY from the normal as it leaves glass and enters air because:

Q125. You can see your face in a polished marble floor but not in a sheet of newspaper, even though both reflect light. The reason is that:

Q126. To see his FULL image, a 1.8 m tall man needs a plane mirror of minimum height:

Q127. The angle between the incident ray and the mirror is θ. The angle between the incident and reflected rays is:

Q128. A ray falls on one of two mirrors placed at 90°, parallel to the second mirror. After both reflections, the outgoing ray is:

Q129. Assertion: A rough wall forms no image. Reason: The laws of reflection are not obeyed on rough surfaces. Choose:

Q130. A mirror is rotated by θ and the reflected ray is found to rotate by 50°. θ is:

Q131. A boy runs at 1.5 m/s AWAY from a plane mirror. The distance between him and his image increases at:

Q132. At what angle should two plane mirrors be inclined so that exactly 11 images of an object are formed?

Q133. A person sees the image of a candle in a plane mirror 5 m away from him; the candle is 2 m in front of the mirror on his side. How far is the PERSON from the mirror?

Q134. Light takes about 1.3 s to reach Earth from the Moon. This light originally came from:

Q135. Two plane mirrors are placed at right angles to each other. A ray strikes the first mirror, reflects onto the second, and leaves it. The emerging ray is:

Q136. A person 1.5 m tall wishes to see a full-length image of themselves in a plane mirror fixed to a wall. The shortest mirror that will do is:

Q137. A wet road at night looks darker to a driver than a dry road. Explain using reflection.

Q138. State the laws of reflection. Describe an activity (as in the NCERT textbook) to verify the first law of reflection.

Q139. Explain, with reasons: (a) why we can see our face in a mirror but not in a newspaper; (b) why the word AMBULANCE is painted laterally inverted on ambulances; (c) why a periscope shows an erect, un-reversed view.

Q140. A ray of light strikes a plane mirror at an angle of 40° to the mirror surface. (a) Find the angle of incidence and the angle of reflection. (b) Find the angle through which the ray is deviated from its original path. (c) If the mirror is now rotated by 5°, keeping the incident ray fixed, through what additional angle does the reflected ray turn?

Q141. A concave mirror has a radius of curvature of 30 cm. An object is placed exactly 30 cm in front of it. The image is:

Q142. A car's rear-view mirror makes following traffic look smaller, and therefore further away, than it really is. This happens because:

Q143. A concave mirror and a convex mirror both have a radius of curvature of 40 cm. In the New Cartesian convention their focal lengths are:

Q144. The minimum distance between an object and its REAL image formed by a concave mirror is:

Q145. A concave mirror produces a magnified REAL image. The object lies:

Q146. Sunlight converges to a bright spot 12 cm from a concave mirror. Its radius of curvature is:

Q147. A driver's mirror shows a bus as a small erect image. As the bus approaches, its image will:

Q148. In a ray diagram, a ray from the object's tip through F reflects parallel, and another through C retraces. They meet 20 cm in front of the mirror. The image is:

Q149. Assertion: A convex mirror can never focus sunlight to burn paper. Reason: Its focus is virtual — rays never actually pass through it.

Q150. A concave mirror of focal length 15 cm forms an image at infinity. The object distance is:

Q151. Consider these statements about a concave mirror. I. It converges a parallel beam to a real focus in front of it. II. It forms a virtual image only when the object lies between the pole and the focus. III. Its focal length is negative in the New Cartesian convention. IV. It always forms a diminished image. Which statements are correct?

Q152. An object is placed at four positions in front of a concave mirror of focal length 10 cm. Which row pairs the position with the image CORRECTLY?

Q153. A convex mirror gives a wider field of view than a plane mirror of the same size because:

Q154. Which of these ray rules for a concave mirror are correct? I. A ray through F reflects parallel to the principal axis. II. A ray through C retraces its own path. III. A ray parallel to the axis reflects through C. IV. A ray striking the pole reflects making equal angles with the axis. Which statements are correct?

Q155. A concave mirror has a focal length of 12 cm. For the image to be real, inverted and exactly the same size as the object, the object must be placed:

Q156. State what happens to the size and position of the image as an object approaches a convex mirror from far away.

Q157. Explain, with the ray rules involved, (a) why the bulb of a torch is placed at the focus of its concave reflector, and (b) why a concave mirror is used by dentists. Draw the reasoning for both (describe the rays in words).

Q158. A concave mirror and a convex mirror each have a radius of curvature of 30 cm. An object is placed 10 cm in front of each mirror. Using the mirror tables (no formula needed), compare the two images formed.

Q159. u = −10 cm for a concave mirror of f = −15 cm. The image is:

Q160. For a convex mirror, which is IMPOSSIBLE?

Q161. A concave mirror (f = −12 cm) must form a real image of magnification −2. The object distance is:

Q162. The image in a mirror is erect and exactly half the object's height. The mirror and m are:

Q163. An object 2 cm tall gives a real image 6 cm tall at 45 cm from a concave mirror. The object distance is:

Q164. Assertion: For mirrors, v and u of a real image are both negative. Reason: Real images form in front of the mirror, on the same side as the object.

Q165. A concave mirror of f = −10 cm forms an image on the object itself. The object distance is:

Q166. A concave mirror forms a REAL image. Which of these are true? I. The object distance u is negative. II. The image distance v is negative. III. The magnification m is negative. IV. The focal length f is positive. Which statements are correct?

Q167. The magnification of a mirror is written m = −v/u rather than v/u because:

Q168. A concave mirror of focal length 20 cm forms an image 60 cm in front of it. The object distance is:

Q169. An object 3 cm tall stands 24 cm from a concave mirror of focal length 8 cm. The height of the image is:

Q170. A concave mirror gives a virtual image twice the size of an object placed 5 cm in front of it. The focal length of the mirror is:

Q171. A convex mirror has a focal length of 15 cm. An object 30 cm in front of it forms an image at:

Q172. A mirror produces a magnification of −2. Which statements are true? I. The image is real. II. The image is inverted. III. The image is twice as tall as the object. IV. The mirror is convex. Which statements are correct?

Q173. An object and its real image formed by a concave mirror are both 36 cm from the mirror. The focal length is:

Q174. Four concave mirrors of focal length 10 cm, 15 cm, 20 cm and 25 cm each have an object placed 30 cm away. The image forms FURTHEST from the mirror for the one of focal length:

Q175. A candle stands between the pole and the focus of a concave mirror. The mirror is moved slowly away until the candle is exactly at the focus. At that moment the image:

Q176. A convex mirror of radius of curvature 24 cm has an object 12 cm in front of it. The magnification is:

Q177. A real image formed by a mirror always has a negative magnification because:

Q178. A concave mirror forms a real, inverted image. Which group lists quantities that are ALL negative?

Q179. An object stands 15 cm from a concave mirror of focal length 10 cm, and the image is caught on a screen. The screen must be placed:

Q180. Can the magnification of a convex mirror ever exceed 1? Justify.

Q181. A student gets v = +15 cm for a concave mirror problem. What kind of image is this, and what must have been true about the object's position?

Q182. An object 4 cm tall is placed 18 cm in front of a concave mirror of radius of curvature 24 cm. Find the position, size and nature of the image.

Q183. Explain the complete method of solving mirror numericals, and show why interpreting the SIGNS of v and m is as important as computing them, using u = −10 cm, f = −15 cm as your example.

Q184. A convex mirror used on a bus has a radius of curvature of 3 m. A car is 5 m behind the bus. Find the position and nature of the car's image, and explain why such mirrors carry the warning 'objects in mirror are closer than they appear'.

Q185. Using the magnification formula alone, explain how you can identify which mirror formed an image, given only the value of m. Cover all the important ranges of m with one example situation each.

Q186. A pond appears 1.5 m deep. If n(water) = 4/3, its REAL depth is:

Q187. Light's speed in medium A is 2 × 10⁸ m/s and in B is 2.5 × 10⁸ m/s. The refractive index of A with respect to B is:

Q188. A ray hits a glass slab at i = 45° and refracts at r = 28°. When it exits the far side, the angle inside the glass at that surface is:

Q189. Assertion: The Sun is visible about two minutes before actual sunrise. Reason: Light bends away from the normal as it leaves the vacuum of space into denser air layers.

Q190. Two slabs, A (thick, n = 1.4) and B (thin, n = 1.4), refract the same ray at the same angle. Compared to B, slab A produces:

Q191. Consider these statements about light passing from air into glass. I. The ray bends towards the normal. II. The speed of the light decreases. III. The frequency of the light changes. IV. A ray along the normal is not deviated at all. Which statements are correct?

Q192. A swimming pool always looks shallower than it really is because:

Q193. Assertion (A): A rectangular glass slab does not split white light into colours. Reason (R): Its two refracting faces are inclined to each other, as the faces of a prism are.

Q194. A ray enters a transparent medium with an angle of incidence of 60° and an angle of refraction of 30°. The refractive index of the medium is about:

Q195. A tank of water of refractive index 4/3 is 2.4 m deep. To someone looking straight down into it, the water appears:

Q196. A glass rod becomes almost invisible when it is dipped into a certain liquid. This tells us that:

Q197. For a ray passing obliquely through a rectangular glass slab, consider these statements. I. The emergent ray is parallel to the incident ray. II. The lateral displacement grows as the slab is made thicker. III. The lateral displacement grows as the angle of incidence is increased. IV. The emergent ray lies along the same straight line as the incident ray. Which statements are correct?

Q198. A student shines a laser straight down onto the surface of a beaker of water and is surprised that the beam does not bend. The correct explanation is that:

Q199. Light takes the same time to cover 3 m in vacuum as it does to cover x metres in a medium of refractive index 1.5. The value of x is:

Q200. A coin lies at the bottom of an empty opaque mug, just out of sight over the rim. Water is poured in without moving the coin, and the coin becomes visible. This happens because: