The flame of a Bunsen burner is _________, when the air hole is open and ___________ when the air hole is closed.
Blue, green
Yellow, blue
Yellow, green
Blue, yellow
Which word equation correctly shows how methane undergoes combustion in a plentiful supply of air?
Methane → Carbon dioxide + Steam
Methane + Oxygen → Carbon dioxide + Hydrogen
Methane + Air → Carbon + Hydrogen
Methane + Oxygen → Carbon dioxide + Steam
Acid rain is caused by _________ and ___________.
Sulphur dioxide & Nitrogen Oxide
Carbon dioxide & Carbon monoxide
Oxygen & Carbon dioxide
None of these
Calorific value of wood is .
Greater than that of diesel
Lesser than that of diesel
Is equal to that of diesel
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
Which zone is the hottest part in a candle flame?
Innermost zone
Middle zone
Outermost zone
Wax zone
An ideal fuel is
Of high calorific value
Of moderate ignition temperature
Economical
All of these
Which one is the best fire extinguisher?
SO2
CO2
NO2
O2
Burning of a matchstick is an example of a __________.
Slow Combustion
Rapid Combustion
Spontaneous Combustion
Good fuels have
Low ignition temperature and high calorific value
Low ignition temperature and low calorific value
High ignition temperature and high calorific value
High ignition temperature and low calorific value.