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

Question-1
__________ is responsible for about 87% of global warming.

(A) Carbon Monoxide	(B) Carbon Dioxide
(C) Nitrogen Oxide	(D) Sulphur Dioxide

Question-2
Which is a fuel?

(A) Wood	(B) Carbon monoxide
(C) Nitrogen	(D) Oxygen

Question-3
___________ zone is the least hot and non-luminous.

(A) Innermost zone	(B) Middle zone
(C) Outermost zone	(D) Wax zone

Question-4
A ____________ is one which is readily available, cheap and burns easily in air at a moderate rate

(A) Good fuel	(B) Ideal fuel
(C) Liquid fuel	(D) Solid fuel

Question-5
Calorific value of wood is .

(A) Greater than that of diesel	(B) Lesser than that of diesel
(C) Is equal to that of diesel	(D) None of these

Question-6
A ______ is a region where combustion of fuel takes place.

(A) Fire	(B) Flame
(C) Vapour	(D) None of these

Question-7
Bio gas is a secondary fuel obtained from .

(A) Coal	(B) Animal dung
(C) Petrol	(D) Wood

Question-8
CNG stands for ___________

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

Question-9
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-10
A burning candle when placed in an enclosed jar immediately gets extinguished. This is because

(A) The supply of CO₂ is cut off	(B) The supply of O₂ is cut off
(C) The supply of N₂ is cut off	(D) Both b &c

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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