Combustion and Flame Test

Result

Combustion and Flame Test - 27

Score
-
out of -
Rank
-
out of -

TIME Taken - -

SHARING IS CARING

If our Website helped you a little, then kindly spread our voice using Social Networks. Spread our word to your readers, friends, teachers, students & all those close ones who deserve to know what you know now.

Weekly Quiz Competition

Question 1
1 / -0

Which of the following is not true about combustion?

A
In case of chimney, when air does not enter from below, the candle burns freely.

B
In case of chimney, candle burns freely when air enters from below the chimney.

C
In case of chimney, when air does not enter from below, the flame flickers and produces smoke.

D
In the absence of air candles flame flickers but does not goes off.

Solution

The statement $$A$$ is not true about combustion.
In case of chimney, when air enters from below, the candle burns freely. If there is no supply of air from below, the candle cannot burn freely. This is because air supply is essential for combustion.
Question 2
1 / -0

Which of the following is not true about combustion?

A
In case of chimney when air does not enters from below, the candle burns freely.

B
In case of chimney candle burns freely when air enters from below the chimney.

C
In case of chimney when air does not enters from below, the flame flickers and produces smoke.

D
In the absence of air candles flame flickers but does not goes off.

Solution

In the case of the chimney when air does not enters from below, the candles flame flickers and produces smoke.
Question 3
1 / -0

Which of the following is the most common fire extinguisher?

A
Foam

B
$$CO_2$$

C
Water

D
Dry powder

Solution

The cheapest and most widely used fire extinguisher is water because it is easily available. But it is preferably used for class A fires, like fire in solids, wood, paper, etc. Not suitable for Class B (Liquid) fires, or where electricity is involved.

Hence, the correct answer is option $$C$$.
Question 4
1 / -0

Which of the following statement is not correct?

A
Air is essential for the burning process

B
The flame of a burning candle can be put off by placing a cover cap over the flame

C
Burning of coal cannot be stopped by covering it with sand

D
Burning of wood can be stopped by covering it with sand

Solution

The burning of coal can be stopped by covering it with sand. When sand is thrown over burning kerosene oil, the sand covers it like a blanket. The sand cuts off the air supply to the burning kerosene oil due to which the fire gets extinguished.
Question 5
1 / -0

The lowest temperature at which a substance catches fire?

A
Flammable temperature

B
Ignition temperature

C
inflammable temperature

D
None of above

Solution

Ignition temperature is the lowest temperature at which a combustible substance when heated (as in a bath of molten metal) takes fire in the air and continues to burn. It is also called also autogenous ignition temperature.
Question 6
1 / -0

Fire produced by oil cannot be controlled by ___________.

A
$$CO_2$$

B
Foam

C
both a and b

D
Water

Solution

Fuels with a specific gravity less than water, such as gasoline or oil, float on water, resulting in the fire continuing in the fuel on top of the water. When water is poured on such liquids it sinks to the bottom where it evaporates and expands rapidly due to which it spreads fire in all directions.
Question 7
1 / -0

_____ is any material that can be made to react so that it releases chemical or nuclear energy as heat.

A
Fossil fuel

B
Fuel

C
Oil

D
All of the above

Solution

A fuel is any material that can be made to react so that it releases chemical or nuclear energy as heat or to be used for work. The heat energy released by reactions of fuels is converted into mechanical energy via a heat engine.
Question 8
1 / -0

How does $$CO_2$$ control fire?

A
Forms a blanket around fire.

B
Brings down temperature of the fuel.

C
Both A and B.

D
None of above.

Solution

When $$CO_2$$ is released from the cylinder, it expands in volume and cools down. Due to this, carbon dioxide forms a blanket around the burning material and makes a barrier between the burning material and oxygen. As oxygen supply is cut off and the temperature goes down, it helps in extinguishing the fire.
Option $$C$$ is correct.
Question 9
1 / -0

What is calorific value?

A
Amount of heat energy produced on complete combustion of 1 kg of fuel.

B
Amount of heat energy produced on complete combustion of 100 kg of fuel.

C
Amount of heat energy consumed on complete combustion of 1 g of fuel.

D
Amount of heat energy consumed on complete combustion of 1 kg of fuel.

Solution

Calorific value is the quantity of heat produced by the complete combustion of 1 kg of a fuel, usually expressed in kilojoules per kilogram (kJ/kg).
Question 10
1 / -0

_______ is a fuel made by compressing natural gas.

A
LPG

B
CNG

C
Both A and B

D
None of above

Solution

Compressed natural gas (CNG) (methane stored at high pressure) can be used in place of gasoline (petrol), diesel fuel, and propane/LPG. CNG is made by compressing natural gas (which is mainly composed of methane, $$CH_4$$), to less than $$1 \%$$ of the volume it occupies at standard atmospheric pressure.

User

Question Analysis

Correct -
Wrong -
Skipped -

My Perfomance

Score
-
out of -
Rank
-
out of -

Re-Attempt Weekly Quiz Competition

Combustion and Flame Test - 27

Result

Combustion and Flame Test - 27

Score

-

Rank

-

SHARING IS CARING

Question 1

In case of chimney, when air does not enter from below, the candle burns freely.

In case of chimney, candle burns freely when air enters from below the chimney.

In case of chimney, when air does not enter from below, the flame flickers and produces smoke.

In the absence of air candles flame flickers but does not goes off.

Solution

Question 2

In case of chimney when air does not enters from below, the candle burns freely.

In case of chimney candle burns freely when air enters from below the chimney.

In case of chimney when air does not enters from below, the flame flickers and produces smoke.

In the absence of air candles flame flickers but does not goes off.

Solution

Question 3

Foam

$$CO_2$$

Water

Dry powder

Solution

Question 4

Air is essential for the burning process

The flame of a burning candle can be put off by placing a cover cap over the flame

Burning of coal cannot be stopped by covering it with sand

Burning of wood can be stopped by covering it with sand

Solution

Question 5

Flammable temperature

Ignition temperature

inflammable temperature

None of above

Solution

Question 6

$$CO_2$$

Foam

both a and b

Water

Solution

Question 7

Fossil fuel

Fuel

Oil

All of the above

Solution

Question 8

Forms a blanket around fire.

Brings down temperature of the fuel.

Both A and B.

None of above.

Solution

Question 9

Amount of heat energy produced on complete combustion of 1 kg of fuel.

Amount of heat energy produced on complete combustion of 100 kg of fuel.

Amount of heat energy consumed on complete combustion of 1 g of fuel.

Amount of heat energy consumed on complete combustion of 1 kg of fuel.

Solution

Question 10

LPG

CNG

Both A and B

None of above

Solution

User

Question Analysis

My Perfomance

Score

-

Rank

-

Results Announcement on: coming Monday

Stay Tuned: We’ll update you on your result via email or SMS.