18. You have to cost the shadow of your pencil on the wall with the help of candle in a dark room. How can you obtain the shadow of same size, small size and big size of the same pencil?

Ans: (a)The shadow of the pencil will be small when the pencil is taken close to the wall and away from the candle. (b)The shadow will be big in size when the pencil is taken closer to the candle. (c)To get the same sized shadow as the pencil is, adjust the distance between the wall, pencil and candle at equal distances.