Q53. What happens when a ray of light falls perpendicularly on the surface of a plane mirror?
Q54. How many images of the coin will be seen when two plane mirrors are set at right angles to each other and a coin is placed in-between these two plane mirrors?
Q55. Image formed by a plane mirror is
(a) virtual, behind the mirror and enlarged
(b) virtual, behind the mirror and of the same size as the object
(c) real at the surface of the mirror and enlarged
(d) real, behind the mirror and of the same size as the object.
Q56. What is the angle of incidence of a ray if the reflected ray is at an angle of 90° to the incident ray?
Q57. What is cataract? How can the vision of a person having cataract be restored?
Q58. Suppose you are in a dark room. Can you see objects in the room? Can you see objects outside the room? Explain.
Q59. Draw a labeled sketch of the human eye.
Q60. How many images of an object will be formed when two plane mirrors are set at an angle of 45°, 60°, 120° and 180°.
Q61. How does eye adjust itself to deal with light of varying intensity?
Q62. Explain why, an owl can see well in the night but not during the day whereas an eagle can see well during day but not in the night.