Explain the formation of a shadow using a point source of light.

Suppose you are crossing a street light at night. At which position will you find your shadow to be longest and shortest? Give a suitable reason for your answer.

Observe the illustration given below which shows three identical wooden objects hanging in front of a torch. Arrange the three in the increasing order of the size of the umbra region formed on the screen kept at the back of the objects. Give a suitable reason for your answer.