What can you see in a completely dark room? If you switch on an electric bulb in this dark room as a light source, explain how you could now see:
(a) The electric bulb
(B) a piece of white paper.
When we see in a completely dark room, we see nothing as there is any light in the dark room.
(a) If we switch on an electric bulb in this dark room as a light source we can see bulb due to the light emitted by it.
(b) If we switch on an electric bulb in this dark room as a light source we can see a piece of white paper as it reflects the light from the bulb falling on it.