Basic Science for Class 8>Chapter 7 - Combustion and Fuels>Exercises>Q B

HARD

8th CBSE

IMPORTANT

Earn 100

Draw a diagram to show the fractional distillation of petroleum.

Important Questions on Combustion and Fuels

HARD

8th CBSE

IMPORTANT

Basic Science for Class 8>Chapter 7 - Combustion and Fuels>Exercises>Q C

Describe an activity to show that a candle burns to give water vapour, carbon dioxide and soot.

MEDIUM

8th CBSE

IMPORTANT

Basic Science for Class 8>Chapter 7 - Combustion and Fuels>Exercises>Q C

Describe a candle flame.

MEDIUM

8th CBSE

IMPORTANT

Basic Science for Class 8>Chapter 7 - Combustion and Fuels>Exercises>Q C

Mention five factors (apart from easy availability at a reasonable price) which should be considered while choosing a fuel.

EASY

8th CBSE

IMPORTANT

Basic Science for Class 8>Chapter 7 - Combustion and Fuels>Exercises>Q D

A log of wood attains the ignition temperature _____ than wood shavings do. (Faster/ Slower)

MEDIUM

8th CBSE

IMPORTANT

Basic Science for Class 8>Chapter 7 - Combustion and Fuels>Exercises>Q D

In the liquid state, hydrogen is used as a fuel in _____. (train / satellite / bus / spacecraft)

HARD

8th CBSE

IMPORTANT

Basic Science for Class 8>Chapter 7 - Combustion and Fuels>Exercises>Q D

Insert the remark ‘good’, ‘better’, ‘best’ or ‘unsuitable’ for the fuels mentioned in the following table.

Fuel	Calorific value (in $k J / g$ )	Ignition temperature (in $^{o} C$ )	Remark
$A$	$100$	$5$
$B$	$80$	$70$
$C$	$70$	$80$
$D$	$60$	$90$

EASY

8th CBSE

IMPORTANT

Basic Science for Class 8>Chapter 7 - Combustion and Fuels>Exercises>Q D

Gaseous fuels are _____ than solid and liquid fuels. (better/worse)

MEDIUM

8th CBSE

IMPORTANT

Basic Science for Class 8>Chapter 7 - Combustion and Fuels>Exercises>Q E

Water is used to extinguish a fire because it