Combustion & Flame

Combustion and flame Worksheet-7

1. Abida and Ramesh were doing an experiment in which water was to be heated in a beaker. Abida kept the beaker near the wick in the yellow part of the candle flame. Ramesh kept the beaker in the outermost part of the flame. Whose water will get heated in a shorter time?

2. Is the food a fuel for our body?

3. Can you burn paper when a burning matchstick is brought near it? Why?

4. Why do different substances catch fire at different temperatures?

5. Why is water poured to extinguish burning wood?

Combustion and flame Worksheet-8

1. (a) Name the type of nuclear reaction taking place in atmosphere of Sun.

(b) Define ignition temperature.

(c) Why water should not be used to put out fire caused by burning of petrol?

2. What are characteristics of an ideal fuel. What is C.N.G.? Mention its one use.

3. Name three types of combustion. Give one example of each.  

4. What is combustion? What are the conditions required for combustion to take place?

Combustion and flame Worksheet-9

6. Explain how water extinguishes the fire.

7. Red buckets containing sand are kept in offices and cinema halls. Why?

8. (a) What is a fuel?

(b) Define calorific value of a fuel.

9. Give reasons.

(a) Water is not used to control fires involving electrical equipment.

(b) LPG is a better domestic fuel than wood.

(c) Paper by itself catches fire easily whereas a piece of paper wrapped around an aluminium pipe does not.