K.C.S.E Physics Q & A - MODEL 2010PP1QN04

K.C.S.E Physics Q & A - MODEL 2010PP1QN04

​A paper windmill in a horizontal axis was placed above a candle as shown in figure 2.

When the candle was lit the paper windmill begun to rotate.
Explain this observation.

answer

•  Flame heats air which becomes less dense and hence moves upwards. This will push the blades upwards and cause clockwise rotation.
• This creates a conventional current