Combustion and Flame

which one of the following gases is used in combustion?

• Hydrogen

• Oxygen

• Carbon-dioxide

• Nitrogen

The minimum temperature at which a material ignites is called

• ignition Temperature

• burning point

• highest temperature

• melting point

The amount of heat energy produced on complete combustion of 1 kg of a fuel is called

• heat value

• internal value

• significant value

• calorific value

which zone represents the partial combustion in candle flame?

• inner zone

• lower zone

• middle zone

• outer zone

Substances which catch fire are called

• burners

• combustible

• bases

• non of these

Which is the hottest part of a flame

• lower

• inner

• middle

• outer

Which zone of a flame does a goldsmith use for melting gold and silver?

• top part

• outer part

• middle part

• inner part

choose any two combustible substances

• wood

• glass

• stone

• charcoal

in what type of matter can a fuel exist

• solid

• liquid

• gas

• all three

Is water combustible?

• Yes

• No