Available Answers

1. 1.

   Choose and write the correct answer(MCQ) :

   1. Compounds containing hydrogen and carbon are called _____________ :
      1. organisms
      2. coal
      3. hydrocarbons 
      4. charcoal 
   2. The main constitutent of coal is ____________ :
      1. carbon
      2. water 
      3. air 
      4. nitrogen 
   3. Natural gas contains methane, about ___________ :
      1. 80%
      2. 30%
      3. 90%
      4. 40%
   4. Combustion requires fuel,oxygen and ____________ :
      1. gas
      2. carbon dioxide
      3. heat
      4. water
   5. The middle zone of a flame is bright ____________ :
      1. darkzone
      2. luminous zone
      3. non-luminous zone
      4. non of these
   6. Flames have different zone of different _____________.
      1. combustion
      2. temperature 
      3. fuels
      4. pollutants 
   7. ____________ is a combustion substance:
      1. stone
      2. cement
      3. kerosene 
      4. pollution 
   8. The ignition temperature of while phosphorus is __________ :
      1. 40°C
      2. 38°C
      3. 35°C
      4. 50°C
2. 2.

   Fill in the blanks.

   1. _________ is smokeless coal.
   2. The ___________ zone of a flame is dark.
   3. Hydrogen burns with a __________ sound.
   4. Fuel can be in the form of a ________, __________ and ___________.
   5. ___________ is obtained by passing steam over red hot cake.
   6. ____________ is the best quality of coal.
   7. Flames have different _________ of different temperature.
   8. The process of burning a fuel is known as __________.
3. 3.

   Write T for true or F for false:

   1. Coal is one of the cheapest and most widely used fuels.
   2. The main constituent of coal is oxygen.
   3. The burning of fossils fuel cause noise pollution.
   4. Petrol is used to run light vehicles.
   5. Global warming leads to greenhouse effect.
   6. Coke contains 89% carbon.
   7. Coal tar is a black-coloured thick liquid.
   8. Petroleum is used to make coal gas.
4. 4.

   Match the column A with column B:

   A	B
   1. Petro	a. Bus
   2. Coal	b. Scooter
   3. Diesel	c. Cooking
   4. LPG	d. Thermal power station
   7. Kerosene	e. Steel industry
   6. Coke	f. Fuel for lamps

    

5. 5.

   Which smelling agent is mixed with butane to detect its leakage?

6. 6.

   Name the three things which combustion requires.