A. Is equal to the heat of formation
B. Is always negative
C. Can’t be known without calculating it
D. Is always positive
Related Mcqs:
- Use of excess of combustion air in the combustion of fuels results in__________________?
A. Heat losses
B. Long flame
C. Condensation of water vapour from the fuel gas
D. None of these - Deficiency of combustion air during combustion of a gaseous fuel_____________________?
A. Lengthens the flame
B. Causes heat loss of fuel by its partial combustion
C. Both A. & B.
D. Shortens the flame - Which of the following has the highest heat of combustion ?
A. H2
B. CO
C. CH4
D. C2H6 - If the specific heat of gaseous products of combustion of a fuel is high, the abiabatic flame temperature will be_____________?
A. Low
B. High
C. Very high, if the fuel is of low calorific value
D. None of these - Net calorific value is the gross calorific value less the _______________ heat of water in the product of combustion when cooled to 15°C ?
A. Sensible
B. Latent
C. Sensible and latent
D. None of these - During combustion of gaseous fuels, deficiency of air_________________?
A. Lengthens the flame
B. Tends to shorten the flame
C. Does not affect the flame length
D. Increases the flame temperature - Spontaneous combustion of coal on storage results due to___________________?
A. Inadequate ventilation
B. Low temperature oxidation
C. Storage in large heaps with small surface to volume ratio
D. All A., B. and C. - Which of the following fuel gases will require maximum amount of air for combustion of 1 Nm3 gas ?
A. Blast furnace gas
B. Natural gas
C. Producer gas
D. Water gas - Efficiency of the combustion of a fuel is judged by the ______________ the flue gas?
A. % of CO2 in
B. % of O2in
C. Temperature of
D. Colour of - Improper storage condition results in the weathering of coal and spontaneous combustion, which increases its_________________?
A. Caking index
B. Yield of carbonised products
C. Friability & oxygen content
D. Calorific value
