Sulphur in coal results in___________________?

Related Mcqs:

1. Which is not correct statement about effect of sulphur in fuel ___________________?

   A. it has heating value
   B. it helps in electrostatic precipitation of ash in flue-gases
   C. it leads to corrosion of air heaters, ducting, etc. if flue gas exit temperature is low
   D. it erodes furnace walls
   E. none of the above

2. Sulphur content of fuels is very important to the plant operators because it____________________?

   A. has high heating value
   B. retards electric precipitation
   C. promotes complete combustion
   D. has highly corrosive effect
   E. facilitates ash removal

3. Sulphur content in diesel oil should not be more than_________________?

   A. 10%
   B. 5%
   C. 1%
   D. 0.1%
   E. 0.01%

4. Sulphur in pig iron tends to make it___________________?

   A. hard’
   B. soft
   C. ductile
   D. tough
   E. malleable

5. Sulphur in steel________________?

   A. acts as deoxidiser
   B. reduces the grain size
   C. decreases tensile strength and hardness
   D. lowers the toughness and transverse ductility
   E. increases hardness

6. The presence of sulphur in pig iron makes__________________?

   A. it easily machinable
   B. it brittle
   C. it hard
   D. the casting unsound
   E. increases the fluidity

7. The coal requirement per kW hour generation in the thermal power plant is of the order of__________________?

   A. 0.1 to 0.2 kg
   B. 0.2 to 0.4 kg
   C. 0.6 to 0.8 kg
   D. 1.0 to 1.5 kg
   E. 1.5 to 2 kg

8. Which is not the correct statement about moisture in coal ______________________?

   A. inherent moisture and surface mois¬ture are different things
   B. in some coals moisture may be present upto 40%
   C. some moisture in coal helps in better burning which is not possible with completely dry coal
   D. it increases thermal efficiency
   E. moisture in coal is removed before firing by heating it with hot air

9. During storage, the heating value of coal __________________?

   A. increases
   B. decreases
   C. remains constant
   D. may increase or decrease depending upon the method of storage
   E. none of the above

10. Calorific value of coal is of the order of _______________________?

    A. 200-400 kcal/kg
    B. 800-1200 kcal/kg
    C. 2000-4000 kcal/kg
    D. 5000-8000 kcal/kg
    E. 8000-10,000 kcal/kg