Question 1

A chemical process in which a substance reacts with oxygen to give off heat is called&#10;A)Conduction&#10;B)Conjunction&#10;C)Combustion&#10;D)Confusion

Accepted Answer

Combustion is the process where a substance reacts with oxygen to produce heat (and often light), such as in a fire or engine.

Question 2

Fuel may be&#10;A)Solid only&#10;B)Solid,Liquid or gas&#10;C)Liquid only&#10;D)Gas only

Accepted Answer

Fuel can exist in solid, liquid, or gas form. Examples include coal (solid), gasoline (liquid), and natural gas (gas).

Question 3

The amount of heat energy produced on complete combustion of_____ fuel is called its calorific value.&#10;A)1 litre&#10;B)1 Kg&#10;C)1 milli litre&#10;D)1 gram

Accepted Answer

Calorific value is defined as the amount of heat energy produced on the complete combustion of 1 kilogram of a fuel.

Question 4

The substances which have very low ignition temperature and can easily catch fire with a flame are called&#10;A)inflammable substances&#10;B)Flaming substance&#10;C)Fire proof substance&#10;D)None of the above

Accepted Answer

Inflammable substances have a very low ignition temperature, making them easily catch fire with a flame.

Question 5

When we heat water in a paper bowl over a candle, the paper does not catch fire because&#10;A)Paper is not inflamable&#10;B)Paper gets wet&#10;C)Due to water the ignition temperature of paper is not reached&#10;D)This is not possible

Accepted Answer

Due to the presence of water, the heat from the candle is absorbed and used to increase the temperature of the water, preventing the paper from reaching its ignition temperature. This is why the paper does not catch fire.

Question 6

When oil or petrol catches fire, water is not used to extinguish it because&#10;A)Water covers oil and oil burns under water layer which may not be noticeable&#10;B)Water is heavier than oil / petrol and so remains below the oil layer which continues to burn&#10;C)Water get mixed with oil and increases fire&#10;D)Water gets evaporated

Accepted Answer

Water is heavier than oil or petrol, so it sinks below the oil layer, allowing the oil to continue burning on the surface.

Question 7

In combustion&#10;A)Both heat and light is produced&#10;B)Only heat is produced&#10;C)Only light is produced&#10;D)All are correct

Accepted Answer

Combustion typically produces both heat and light, as seen in fires or burning substances.

Question 8

A person caught fire on clothes is wrapped with blanket because&#10;A)The person suddenly feels cold&#10;B)To hide the burnt body parts&#10;C)The person's clothes gets burnt&#10;D)To reduce air supply and put fire off

Accepted Answer

The answer of A person caught fire on clothes is...

Question 9

Ignition temperature is&#10;A)The maximum temperature at which a substance catches fire&#10;B)The minimum temperature at which a substance catches fire&#10;C)The temperature of burning substance&#10;D)The temperature in the substance when

Accepted Answer

The ignition temperature is the minimum temperature at which a substance catches fire without being provided any external flame or spark. It is the point at which the substance spontaneously ignites.

Question 10

Explosion takes place because of&#10;A)Release of large amount of gas under pressure due to sudden reaction&#10;B)Release of large amount of heat&#10;C)Release of large amount of light&#10;D)None of the above

Accepted Answer

An explosion occurs primarily due to the rapid release of a large amount of gas under pressure, which is often the result of a sudden chemical reaction.

Deck 1: Combustion and Flam: Combustion and Fire Safety