1. Place two candles on a table.
2. Ensure that both the candles are of same size and height.
3. Mark them as candle 1 and candle 2 using a chalkpiece.
4. Light both the candles. Now, cover candle 2 with glass tumbler as shown in the figure.
5. Observe the happenings at both the candle.
6. The candle 1 continues to bum, unless it is blown – off by strong moving air or any other external force.
7. This is because fresh air is continuously available to the candle for its burning process.
8. Candle 2 glows for a while and then gets put – off.
9. When the burning candle is covered with a glass tumbler, the candle can use the oxygen available in the air inside the glass tumbler.
10. Since only a small amount of air is present inside the glass tumbler – only a small portion of oxygen is available for the candle to continue glowing.
11. When all the oxygen of the air inside the gas jar is used up, then the burning candle gets extinguished.