Combustion and Flame (CBSE Class-8 Science): Questions 22 - 27 of 33

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Question number: 22

» Combustion and Flame » Fuel » Ideal Fuel

MCQ▾

Question

Amongst the three states of fuel which state of the fuel is considered best?

Choices

Choice (4) Response

a.

Solid

b.

Gaseous

c.

Liquid

d.

None of the above

Question number: 23

» Combustion and Flame » Fuel » Introduction to Fuel

MCQ▾

Question

Wastage of LPG can be reduced by:

Choices

Choice (4) Response

a.

Reduce the flame through control knob

b.

Use of pressure cooking devices

c.

Switch on burning device after placing the container on the burner

d.

All a. , b. and c. are correct

Question number: 24

» Combustion and Flame » Fuel » Fuel Efficiency

MCQ▾

Question

Fuel efficiency is:

Choices

Choice (4) Response

a.

The maximum energy which a given fuel can give leaving very little residue

b.

Lowest temperature at which a substance catches fire

c.

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

d.

Question does not provide sufficient data or is vague

Question number: 25

» Combustion and Flame » Flame » Structure of a Flame

MCQ▾

Question

Part of the candle flame which is least hot and black in colour is:

Choices

Choice (4) Response

a.

Zone C

b.

Innermost region

c.

Zone B

d.

Both a. and b. are correct

Question number: 26

» Combustion and Flame » Combustion » Process of Combustion

MCQ▾

Question

Combustion is defined as:

Choices

Choice (4) Response

a.

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

b.

Substance which produces energy

c.

Substance which vapourise during burning form a flame

d.

Chemical process in which a substance react with oxygen to give off heat

Question number: 27

» Combustion and Flame » Flame » Structure of a Flame

MCQ▾

Question

Zone of the candle flame which is yellow in colour is:

Choices

Choice (4) Response

a.

Innermost zone

b.

Zone B

c.

Middle zone

d.

Both b. and c. are correct

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