Questions
What is ignition temperature?
- Time required for a material to burn out completely
- Lowest temperature at which a substance catches fire
- A higher temperature, which will cause it to burn faster
- Time required for the fire to be put out
- Temperature at which the fire is put out
A person's clothes are on fire. Which of the following should be done?
- Ask the person to run around so that the fire will be put out
- Pour water on him
- Cover the person with a blanket
- Ask the person to move around slowly
Why a match stick does not catch fire on its own at room temperature?
- Because catalyst is absent.
- Because sunlight is needed.
- Because phosphorus is absent on match stick.
- Because room temperature is lower than ignition temperature of the matchstick.
- Because carbon dioxide in the air prevents combustion.
Which of the following is not an inflammable substance?
- Wood
- Alcohol
- Petrol
- Liquid ammonia
- LPG
Water should not be used to extinguish the fire in case of
- a wooden house on fire
- an electrical equipment on fire
- fire in a paper mill
- fire in a godown with grains
- forest fire
CNG is a better fuel than petrol or diesel in automobiles. Which of the following is not a correct reasoning for this statement?
- CNG burns more efficiently.
- It is expensive.
- It cannot be siphoned off by thieves.
- CNG produces less harmful products.
- It is cheaper.
When fire fighters pour water to put out fire, which of the following does not happen?
- Water cools the material.
- It prevents fire from spreading.
- Temperature is brought below ignition temperature.
- Water vapours around the material cuts off supply of air.
- Water splits to give oxygen.
Which of the following is not an example of spontaneous combustion?
- Phosphorus burning in air
- Forest fire due to lightning
- Burning of charcoal
- Combustion of coal dust in a coal mine
- Forest fire due to heat of the sun
Which fuel is used by fire dancers who perform acts like fire breathing?
- Kerosene
- Petrol
- Aviation fuel
- Alcohol
- Diesel
Oxides of sulphur and nitrogen are produced by burning of fossil fuels. These two oxides are the major culprits for______________ phenomenon.
- greenhouse effect
- el-nino effect
- acid rain
- eutrophication
- bio-geo chemical cycles
Which gas is linked to global warming?
- Oxides of nitrogen
- Ozone
- Oxides of sulphur
- Hydrogen sulphide
- Carbon dioxide
Calorific value of a fuel is
- time needed for one kilogram of fuel to be burnt out completely
- change in state of the fuel
- time needed for half kilogram of fuel to be burnt out completely
- amount of heat energy produced on complete combustion of one kilogram of fuel
- heat energy needed to burn the fuel
Fire broke out in a kitchen. The lady in the house did not have a fire extinguisher, but she was wise enough to use a dry chemical in her kitchen to put out the fire. What material could she use?
- Salt
- Chilli powder
- Sugar
- Baking soda
- Turmeric powder
A few people were staying in a room. On a cold night, when there was no electricity, one of them suggested that they burn coal in the room in order to get warmth. The others immediately declined this option. What could be the reason for this?
- Carbon monoxide is produced.
- Coal is expensive.
- Black soot will get deposited.
- Carbon dioxide is produced.
- Coal will get over-heated.