When the coal is heated in absence of air, it is called its ________________?

Related Mcqs:

1. Coal is heated in absence of air for 7 minutes at a temperature of about ______________ °C, during its volatile matter determination for proximate analysis?

   A. 550
   B. 750
   C. 950
   D. 1150

2. Coal is heated in presence of air to a temperature of about _______________ °C, while determining its ash content for proximate analysis?

   A. 500
   B. 750
   C. 950
   D. 1100

3. Calorific value of coal middling generated in coal washeries during washing of coal may be around _____________ Kcal/kg?

   A. 1000
   B. 4000
   C. 6000
   D. 8000

4. Combustion of pulverised coal as compared to that of lump coal ________________?

   A. Develops a non-luminous flame
   B. Develops a low temperature flame
   C. Can be done with less excess air
   D. Provides a lower rate of heat release

5. Commercial production of petrol from coal (as practised in a factory at Sasol in South Africa) is done by the ________________ of coal?

   A. Hydrogenation
   B. Gasification
   C. Carbonisation
   D. None of these

6. Ratio of primary air to secondary air increases with increase in the rank of coal, because the__________________?

   A. High rank coals have higher amount of volatile matter
   B. Ratio of fixed carbon to volatile matter increases
   C. Oxygen content progressively decreases
   D. Calorific value of the coal increases

7. When steam is passed over coal resulting in the endothermic reaction represent by, C + H2O = CO + H2, it is called the _______________ of coal?

   A. Carbonisation
   B. Oxidation
   C. Coalification
   D. Gasification

8. A coal containing very high percentage of durain is called ______________ coal?

   A. Bright
   B. Splint
   C. Non-banded
   D. Boghead

9. Prime coking coal is always blended with medium or non- coking coal before carbonisation__________________?

   A. To check against its excessive swelling during heating, which may exert high pressure and
   damage coke oven walls
   B. Because, it alone produces unreactive coke
   C. Both A. and B.
   D. Neither A. nor B.

10. The liquid used for the washing of coal in an industrial coal washery is a mixture of water and ____________________?

    A. Carbon tetrachloride
    B. Sand (40%)
    C. Mineral oil of high viscosity & specific gravity (1.6)
    D. None of these