What are luminous and non-luminous bodies?
Give examples. Answer: Luminous Bodies: Those objects which emit their own light are celled luminous bodies e.g. sun, stars, burning fire, radium, etc. Non-luminous bodies: Those objects which do not emit light of their own but shine due to other luminous bodies are called non-luminous bodies. They are visible only when light falls on them. e.g. Moon, earth and other planets, things in a room. Q3. Write some properties of a magnet. Answer: Properties of a magnet: 1. A magnet attracts magnetic materials. 2. A freely suspended magnet always points in north-south direction. 3. Like poles of a magnet repel each other whereas unlike poles attract each other. 4. A magnet can be magnetized by rubbing it with a permanent magnet. 5. The poles of a magnet can never be isolated. 6. When a piece of iron is brought near a magnet, it behaves like a magnet. Q4. Does the earth behave like a huge magnet. Justify your answer. Answer: A freely suspended magnet always comes to rest in the north-south dire