Combustion and Flame (CBSE Class-8 Science): Questions 17 - 22 of 33

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Question number: 17

» Combustion and Flame » Flame » What Is Flame

MCQ▾

Question

Which types of substances form flame?

Choices

Choice (4) Response
a.

Combustible substance which produces energy when burnt

b.

Combustible gas burns rapidly and produces heat and light

c.

Combustible substances which vaporise during burning form a flame

d.

Combustible substances which have very low ignition temperature and can easily catch fire.

Question number: 18

» Combustion and Flame » Fuel » Ideal Fuel

MCQ▾

Question

Examples of fuels used in industries are:

Choices

Choice (4) Response
a.

Water gas

b.

Producer gas

c.

Natural gas

d. Both a. and b. are correct

Question number: 19

» Combustion and Flame » Types of Combustion » Spontaneous Combustion

MCQ▾

Question

Phosphorescence is an example of:

Choices

Choice (4) Response
a.

Rapid combustion

b.

Explosion

c.

Spontaneous combustion

d. Question does not provide sufficient data or is vague

Question number: 20

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

MCQ▾

Question

Global warming is produced due to the presence of gas, excess amount of

Choices

Choice (4) Response
a.

SO2 and NO2

b.

Carbon monoxide

c.

Carbon dioxide in air

d. Question does not provide sufficient data or is vague

Question number: 21

» Combustion and Flame » Fuel » Introduction to Fuel

MCQ▾

Question

Calorific value of a fuel depends upon:

Choices

Choice (4) Response
a.

Amount of ash and water it contains

b.

Chemical composition

c.

Physical state of the fuel

d. Both a. and b. are correct

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

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