(b) the leaves are circular
   (c) the rays bend to form circular spots
   (d) the gaps between the leaves act as pin holes
Ans: (d)
162. The completely dark portion of a shadow of an object is known as
   (a) umbra
   (b) penumbra
   (c) image
   (d) black portion of light
Ans: (a)
163. A solar eclipse occurs when the earth, the sun and the moon are in a
   straight line, and
   (a) when the moon passes between the sun and the earth
   (b) when the sun comes between the earth and the moon
   (c) when the earth comes between the sun and the moon
   (d) on a full moon day
Ans: (a)
164. The image formed by a plane mirror is
   (a) of the same size as the object
   (b) at the same distance behind the mirror as the object is in front of it
   (c) virtual and laterally inverted
   (d) All the above
Ans: (d)
165. To get 5 images of a single object one should have two plane mirrors
   inclined at an angle of
   (a) 72°
   (b) 60°
   (c) 36°
   (d) 90°
Ans: (b)
166. Formation of shadows can be explained by
   (a) rectilinear propagation of light