Available Answers

1. 1.

   Tick the picture of the object which can burn easily.

   

2. 2.

   Fill in the blanks.

   1. _______________ gas supports combustion.
   2. _______________ is a poisonous gas which is produced due to incomplete combustion.
   3. _______________ gas helps in extinguishing fire.
   4. _______________ and _______________ are the products of combustion.
   5. Most fuels are made up of _______________ and _______________.
3. 3.

   Tick (√) the correct options.

   1. Which of these is a necessary condition for combustion?
      1. A combustible substance
      2. Supply of oxygen
      3. Both (i) and (ii)
      4. None of the above
   2. In which of the following cases, complete combustion takes place?
      1. Inadequate supply of oxygen
      2. Adequate supply of oxygen
      3. Inadequate supply of carbon dioxide
      4. Adequate supply of carbon dioxide
   3. Which of the following is not a function of a fire extinguisher?
      1. It reduces the ignition temperature
      2. It causes the flame to burn brighter
      3. It cuts off the supply of oxygen
      4. All the above
   4. Carbon monoxide gas is formed due to the incomplete combustion of
      1. petrol
      2. coal
      3. diesel
      4. kerosene
   5. In case of an electrical fire, the extinguisher we use is
      1. carbon dioxide gas
      2. water
      3. oil
      4. salt
4. 4.

   Match the columns.

   COLUMN A	COLUMN B
   1. Non-polluting fuel	a. Yellow flame
   2. Luminous flame	b. Blue flame
   3. White phosphorus	c. LPG
   4. Non-luminous flame	d. Spontaneous combustion
   5. Liquid fuel	e. CNG

    

5. 5.

   Give two examples for each the following.

   1. Substances used as fire extinguishers
   2. Zones of a flame
   3. Two substances which show rapid combustion
   4. Two substances which are non-combustible in nature
   5. Two inflammable substances
6. 6.

   Define combustion.