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Question-1
Which one of these not a condition for combustion to happen?

(A) Combustible substance	(B) Surrounding medium
(C) Ignition temperature	(D) All of these

Question-2
Which among the following is the best fuel?

(A) Wood 4000 Cal/g	(B) Coke 8000 Ca/g
(C) Coal 7000 Cal/g	(D) Kerosene 11,200 Cal/g

Question-3
Combustion stops if the supply of ________ is cut off.

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

Question-4
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-5
The conditions necessary for combustion are:

(A) presence of combustible substance	(B) presence of supporter of combustion
(C) attainment of ignition temperature	(D) all of these

Question-6
Which one of the following is/are combustible substances?

(A) Wood	(B) Paper
(C) Sand	(D) Both a and b

Question-7
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-8
Water cannot be used as fire extinguisher to put out:

(A) burning wood	(B) burning oil
(C) burning cloth	(D) burning charcoal

Question-9
Combustion in which large amounts of heat and light energy are released which often results in fire is called .

(A) Slow combustion	(B) Spontaneous combustion
(C) Rapid combustion	(D) None of these

Question-10
Methane burns in air to form:

(A) C0₂+H₂0	(B) C0₂+H₂
(C) CO+O₂	(D) CO₂÷O₂-i-heat

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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