Question

In a room lighted by an electric bulb, it is found that the shadow of the ceiling fan hung in the centre is falling on a wall opposite to the door. What can you say about the position of the bulb?

• A. On the wall having the door
• B. On the wall facing the door
• C. On the wall on your right as you enter the room
• D. On the wall on your left as you enter the room

Answer 1

The correct option is A On the wall having the door

Answer is A.

When we put any object in between the light source it forms a shadow of that object. The closer the object is to the source of the light, the more light it blocks out, so its shadow is bigger. But if the object is further away, it does not block out much light, and so the shadow is smaller.
Therefore, for the shadow of the ceiling fan to be formed on a wall opposite to the door, the electric bulb must be positioned on the wall having the door.