# Mechanical Engineering - Steam Boilers and Engines

36.
The boiler efficiency is given by (where m = Total mass of water evaporated into steam in kg/h, mf = Mass of fuel in kg/h, C = Calorific valve of fuel in kJ/kg of fuel, h = Total heat of steam in kJ/kg, and hf1 = Sensible heat of feed water in kJ /kg)
Explanation:
No answer description is available. Let's discuss.

37.
In a boiler, the heat is lost
to dry flue gases
in moisture present in the fuel
to steam formed by combustion of hydrogen per kg of fuel
all of the above
Explanation:
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38.
The crown of the fire box is made hemispherical in order to resist intense heat in the fire box.
True
False
Explanation:
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39.
For maximum discharge through a chimney, the condition is that height of hot gas column producing the draught should be
one-half the height of chimney
equal to the height of chimney
two times the height of chimney
four times the height of chimney