Quiznetik
Combustion and Flame | Set 1
1. A chemical process in which a substance reacts with oxygen to give off heat is called
A. Conduction
B. Conjunction
C. Combustion
D. Confusion
Correct : C. Combustion
2. Fuel may be
A. Solid only
B. Solid,Liquid or gas
C. Liquid only
D. Gas only
Correct : B. Solid,Liquid or gas
3. The amount of heat energy produced on complete combustion of_____ fuel is called its calorific value.
A. 1 litre
B. 1 Kg
C. 1 milli litre
D. 1 gram
Correct : B. 1 Kg
4. The substances which have very low ignition temperature and can easily catch fire with a flame are called
A. inflammable substances
B. Flaming substance
C. Fire proof substance
D. None of the above
Correct : A. inflammable substances
5. When we heat water in a paper bowl over a candle, the paper does not catch fire because
A. Paper is not inflamable
B. Paper gets wet
C. Due to water the ignition temperature of paper is not reached
D. This is not possible
Correct : C. Due to water the ignition temperature of paper is not reached
6. When oil or petrol catches fire, water is not used to extinguish it because
A. Water covers oil and oil burns under water layer which may not be noticeable
B. Water is heavier than oil / petrol and so remains below the oil layer which continues to burn
C. Water get mixed with oil and increases fire
D. Water gets evaporated
Correct : B. Water is heavier than oil / petrol and so remains below the oil layer which continues to burn
7. In combustion
A. Both heat and light is produced
B. Only heat is produced
C. Only light is produced
D. All are correct
Correct : A. Both heat and light is produced
8. A person caught fire on clothes is wrapped with blanket because
A. The person suddenly feels cold
B. To hide the burnt body parts
C. The person’s clothes gets burnt
D. To reduce air supply and put fire off
Correct : B. To hide the burnt body parts
9. Ignition temperature is
A. The maximum temperature at which a substance catches fire
B. The minimum temperature at which a substance catches fire
C. The temperature of burning substance
D. The temperature in the substance when
Correct : B. The minimum temperature at which a substance catches fire
10. Explosion takes place because of
A. Release of large amount of gas under pressure due to sudden reaction
B. Release of large amount of heat
C. Release of large amount of light
D. None of the above
Correct : A. Release of large amount of gas under pressure due to sudden reaction