CBSE Class-8 Science: Questions 168 - 174 of 469

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Question number: 168

» 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: 169

» 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: 170

» 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

Question number: 171

» Coal and Petroleum » Coal » Coke and Coal Tar

MCQ▾

Question

Coal tar is used in:

Choices

Choice (4) Response

a.

Dyes, explosive, drugs

AND

Synthetic fibres, pesticides

b.

On the surface of metalled road

c.

Naphthalene balls and moth balls

d.

All a. , b. and c. are correct

Question number: 172

» Combustion and Flame » Fire » Fire Extinguisher

MCQ▾

Question

Types of fire that cannot be controlled by throwing water are:

Choices

Choice (4) Response

a.

Fire produced by crackers

b.

Fire produced by burning of oil or petrol

c.

Fire produced by electric short circuit

d.

Both b. and c. are correct

Question number: 173

» Combustion and Flame » Fuel » Burning of Fuels Leads to Harmful Products

MCQ▾

Question

Burning of coal, diesel and petrol releases gases like:

Choices

Choice (4) Response

a.

Water gas

b.

CO2, CO

c.

SO2 and NO2

d.

Producer gas

Question number: 174

» Combustion and Flame » Fuel » Introduction to Fuel

MCQ▾

Question

On the basis of physical state fuels are divided in:

Choices

Choice (4) Response

a.

Raw fuels and processed fuels

b.

Natural fuels and manufactured fuels

c.

Solid fuels, Liquid fuels, gaseous fuels

d.

Both a. and b. are correct

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