Why is carbon dioxide used in fire extinguishers?

Important Questions on Combustion, Flame and Fuels

MEDIUM

8th CBSE

IMPORTANT

Expanded Universal Science>Chapter 6 - Combustion, Flame and Fuels>ASSESSMENT ZONE>Q D

Classify the fuels on the basis of their use.

MEDIUM

8th CBSE

IMPORTANT

Expanded Universal Science>Chapter 6 - Combustion, Flame and Fuels>ASSESSMENT ZONE>Q D

Why are lead compounds harmful to us?

MEDIUM

8th CBSE

IMPORTANT

Expanded Universal Science>Chapter 6 - Combustion, Flame and Fuels>ASSESSMENT ZONE>Q D

Why is soda-acid fire extinguisher not effective when oil catches fire?

EASY

8th CBSE

IMPORTANT

Expanded Universal Science>Chapter 6 - Combustion, Flame and Fuels>ASSESSMENT ZONE>Q D

Which of the following compounds has least calorific value. (biogas, wood, kerosene, LPG).

EASY

8th CBSE

IMPORTANT

Expanded Universal Science>Chapter 6 - Combustion, Flame and Fuels>ASSESSMENT ZONE>Q D

Why is LPG labelled as inflammable substance?

EASY

8th CBSE

IMPORTANT

Expanded Universal Science>Chapter 6 - Combustion, Flame and Fuels>ASSESSMENT ZONE>Q D

What is calorific value? Write its unit.

MEDIUM

8th CBSE

IMPORTANT

Expanded Universal Science>Chapter 6 - Combustion, Flame and Fuels>ASSESSMENT ZONE>Q D

In an experiment 5 kg of a fuel was completely burnt. The heat produced was measured to be 1,80,000 KJ. Calculate the calorific value of the fuel.

MEDIUM

8th CBSE

IMPORTANT

Expanded Universal Science>Chapter 6 - Combustion, Flame and Fuels>ASSESSMENT ZONE>Q D

Suppose you are asked to cook rice using cow dung cake, coal and LPG as fuels. Which fuel would you prefer? Give your reason.