Combustion in which large amounts of heat and light energy are released which often results in fire is called .
Slow combustion
Spontaneous combustion
Rapid combustion
None of these
Arrange the following in terms of their increasing fuel efficiency
i) Wood,ii) Coal,iii) LPG, iv) Diesel
i < ii < iv<iii
ii < i < iv < iii
iii < iv < ii < i
iv < iii < ii< i
Combustion is nothing but _________ of fuels.
Burning
Heating
Lighting
Reaction
________ fuels do not leave any residue after burning.
Solid
Gaseous
Liquid
Primary
When ignition temperature of a substance is _____ it will readily catch fire.
Low
High
Constant
Medium
Combustion stops if the supply of ________ is cut off.
Nitrogen
Oxygen
Carbon dioxide
Hydrogen
Water gas, furnace oil and charcoal are examples of _________.
Primary fuels
Secondary fuel
Non-renewable
While burning of fuel, which of the following gas is not emitted.
Sulphur dioxide
Carbon monoxide
Why doesn't matchstick burn by itself, eventhough it is a combustible substance?
It gets ignited due to the heat of friction
A combustible substance cannot catch fire below is ignition temperature.
Both a & b
Bio gas is a secondary fuel obtained from .
Coal
Animal dung
Petrol
Wood
