Question

C. Write T for true and 'F for false :
1. All combustible substances give flame while burning..............

2. CNG is a clean fuel...............

3. The calorific value of a fuel determines its efficiency.............

4. Incomplete combustion of a fuel gives poisonous carbon monoxide gas................

5. Water is one of the best fire extinguisher used to extinguish all kinds of fire............​

Answer 1

Answer:

1. False

2. True

3. True

4. True

5. False

Explanation:

Hope this helps!

Answer 2

Answer:

1.False

2.true

3.false

4.true

5.false

Explanation

1.We find that a combustible substance cannot catch fire or burn as long as its temperature is lower than its ignition temperature. ... Kerosene oil and wood do not catch fire on their own at room temperature. But, if kerosene oil is heated a little, it will catch fire.

2.CNG is one of the cleanest burning fuels available. The use of CNG reduces carbon monoxide emissions 90 to 97 percent.

3.Calorific value (CV) is a measure of heating power and is dependent upon the composition of the gas. The CV refers to the amount of energy released when a known volume of gas is completely combusted under specified conditions.

4.Incomplete combustion occurs when the supply of air or oxygen is poor. Water is still produced, but carbon monoxide and carbon are produced instead of carbon dioxide. The carbon is released as soot . Carbon monoxide is a poisonous gas, which is one reason why complete combustion is preferred to incomplete combustion

5.Water extinguishers are only suitable for Class A fires consisting of paper, wood, straw, coal, rubber, solid plastics and soft furnishings. ... A drawback is that they cannot be used on burning fat or oil (Class F), burning metals (Class D), burning liquids (Class B) or electrical appliance fires.

HOPE THAT HELPS YOU :)