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

Question-1
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

Question-2
Which of the following gases cause acid rain?

I. Ammonia

II. Hydrogen

III. Oxides of Nitrogen

IV. Sulphur dioxide

(A) I and II only	(B) II and IV only
(C) III and IV only	(D) All of these

Question-3
In foam type extinguisher______ is present in bottle.

(A) NaHCO₃	(B) Al₂(SO₄)₃
(C) Al(OH)₃	(D) Na₂5O₄

Question-4
Mark the corret statement.

(A) Different substances catch fire at the same temperature.	(B) Different substances catch fire at different temperatures
(C) Same substances can catch fire at different temperatures.	(D) None of these

Question-5
Increased percentage of carbon dioxide in air has been linked to __________

(A) Increased Rain	(B) Global warming
(C) Earthquake	(D) Forest fire

Question-6
Bio gas is a secondary fuel obtained from .

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

Question-7
Which zone is the hottest part in a candle flame?

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

Question-8
_________ fuels gets exhausted over a period of time.

(A) Non-renewable	(B) Renewable
(C) Primary	(D) Secondary

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
Which one of these is/are essentials of a fire?

(A) Heat	(B) Fuel
(C) Oxygen	(D) All of these

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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