A. Calorific value increases sometimes
B. Bulk density always decreases
C. Clinkering tendency during combustion increases
D. None of these
Related Mcqs:
- With increase in moisture content of coal, its___________________?
A. Calorific value increases
B. Caking properties diminish
C. Swelling during carbonisation becomes excessive
D. None of these - As the equilibrium moisture content of the coal increases, its___________________?
A. Calorific value increases
B. Swelling number decreases
C. Swelling number increases
D. Bulk density decreases - Mineral matter content (M) and ash content A. in coal are approximately related as _______________?
A. M = 1.1A
B. M = A
C. M = 1.5A
D. M = 2A - 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 - With increase in the oxygen content of the coal, its ______________ decreases?
A. Calorific value
B. Caking power
C. Both A. & B.
D. Neither A. nor B. - Fusion point of coal ash increases with increase in its ____________ content?
A. Iron sulphate
B. Iron silicate
C. Lime and magnesia
D. All A., B. and C. - Presence of free moisture in coal is most disadvantageous during_________________?
A. Its pulverisation (as it requires more power)
B. Combustion of fire slacks on the grates
C. Handling (e.g. when emptying wagons)
D. None of these - Presence of free moisture in coal during its high temperature carbonisation _____________________?
A. Reduces the coking time
B. Protects the volatile products from pyrolysis (cracking) in the presence of hot coke and hot
oven walls
C. Increases the loss of fine coal dust from the ovens when charging
D. None of these - Presence of force moisture in coal is most disadvantageous during its __________________?
A. Transportation and handling
B. Washing
C. Pulverisation
D. Storage - 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
