CHAPTER 6 COMBUSTION AND FLAME

Q1. Fill the following table with examples of stated fuels:-

SR. NO

SOLID FUELS

LIQUID FUELS

GASEOUS FUELS

1.

2.

3.

4.

Q II. Choose the correct option :-

1] Which of the following has the lowest ignition temperature.

a) petrol b) kerosene c) coal d) LPG

2] The substance having highest calorific value is

a) LPG b) hydrogen c) oxygen d) coal gas

3] The natural solid fuel is

a) coal b) coke c) LPG d) charcoal

4] The zone of the candle which is moderately hot is called

a) nonluminous zone b) luminous zone c) inner dark zone d) lowest blue zone

5] Which of the following causes acid rain

a) carbon dioxide b) Sulphur trioxide

c) Carbon monoxide d) oxides of sulphur & nitrogen

6] For the combustion reaction the temperature of the material should be

a) lower than the ignition temperatureb) higher than the ignition temperature

c) equal to the ignition temperature d) none of the above

7] Who were the people who introduced match sticks

a) Indians b) Americans c) Egyptians d) British

8] Which of the following causes death if inhaled in large amounts

a) carbon dioxide b) carbon monoxide c) nitrogen dioxide d) sulphur dioxide

9] Which of the following is an example of rapid combustion

a) burning of charcoal pieces b) burning of wicks dipped in kerosene

c) burning of cow-dung cakes d) burning of a match stick

10] Which of the following gives a pollution free environment when burnt

a) dung cake b) kerosene c) wood d) biogas

Q III. Fill in the blanks : -

1. A material that burns is one that can combine quickly with ______________________ .

2. A _________________________ is produced when combustible substance is in the vapour state.

3. Energy crisis can be prevented by slowing down the use of _______________________ .

4. Combustion is an ________________________ process.

5. The increase in the global temperature due to use of fossil fuels is called _____________________.

QIV. State two differences between rapid and spontaneous combustion

QV. Recognise the following and state the objective of performing the activity.

[A] [B]