A burning incense stick is fixed, pointing downwards. In which direction would the smoke from the incense stick move? Show the movement of smoke with a diagram.
The smoke from the burning incense stick will move upwards. Smoke is a mixture of hot gases and tiny solid particles released when something burns. Since the smoke is warmer than the surrounding air, it expands, becomes lighter, and rises upward due to convection. The diagram should show an incense stick pointing downwards with arrows indicating smoke rising upward from the burning tip.
Explanation
The chapter states: 'You must have observed that when an incense stick (agarbatti) is burnt, smoke rises up. Smoke is a mixture of hot gases and tiny solid particles that are released when something burns. As it is warmer than the surrounding air, it rises up.' This demonstrates the principle of convection where hot air rises because it is lighter than the surrounding cooler air.