CBSE Std 8 Study Materials, Online Learning, Question Papers, Classnotes, Practice Test, MCQ | Smartindia Educational Program : www.smartindia.net.in

Question-1
CNG stands for ___________

(A) Compressed Natural Gas	(B) Compressed Nitrogen Gas
(C) Complete Natural Gas	(D) Complete Nitrogen gas

Question-2
The heat produced by burning 1 g of fuel completely is known as:

(A) heat capacity	(B) calorific value
(C) vapour density	(D) boiling point

Question-3
Combustion is nothing but _________ of fuels.

(A) Burning	(B) Heating
(C) Lighting	(D) Reaction

Question-4
The process of burning a substance in the presence of air with the evolution of heat is called:

(A) distillation	(B) carbonisation
(C) combustion	(D) refining

Question-5
The flame of a Bunsen burner is _________, when the air hole is open and ___________ when the air hole is closed.

(A) Blue, green	(B) Yellow, blue
(C) Yellow, green	(D) Blue, yellow

Question-6
Fire brigade uses which of the following first at a fire accident site?

(A) Fire extinguisher	(B) Carbon dioxide
(C) Water	(D) Sand

Question-7
Combustion stops if the supply of ________ is cut off.

(A) Nitrogen	(B) Oxygen
(C) Carbon dioxide	(D) Hydrogen

Question-8
Which of the following are requirements for producing fire?

(A) Oxygen and heat	(B) Fuel and oxygen
(C) Fuel, oxygen and heat	(D) Fuel and heat

Question-9
On the complete combustion of methane we get a material that is

(A) Acidic	(B) Basic
(C) Neutral	(D) Solid

Question-10
Oxides of sulfur and nitrogen dissolve in rain water and form acids such rain is called__________

(A) Acid rain	(B) Chemical rain
(C) Global warming	(D) Fuels

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Std 8

CBSE

Practice in Related Chapters
Combustion,flame and fuel
Coal and Petroleum
Synthetic Fibres and Plastics
Pollution of Air and Water
Metals and Non-Metals