Suppose you are in a dark room. Can you see objects in the room? Can you see objects outside the room? Explain.
Explanation
So if there is no light we will not able to see, if there is light we will able to see.
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.