3077. Mineral matter, ‘M’ and ash percentage ‘A’ in coal are roughly related as
M = 1.8 A
M = 0.5 A
M = 1.1 A
M = A
✅ The correct answer is option C.
3080. ‘Fuel’ can be defined as a substance which produces heat by
Combustion
Nuclear fission
Nuclear fusion
All of the above
✅ The correct answer is option D.
3083. Gross and net calorific value of a fuel will be the same
If its ash content is zero
Ifits carbon content is very low
If its hydrogen/hydrogen compound content is zero
Under no circumstances
✅ The correct answer is option C.
3089. Producer gas containing least amount of tar is produced by the
Partial combustion of coal
Partial combustion of large size (< 50 mm) coke
High pressure gasification of coal (e.g. in Lurgi gasifier)
Atmospheric pressure gasification of coal (e.g., in Kopper-Totzek gasifier)
✅ The correct answer is option B.
3094. The main reason for making the copper calorimeter (used in bomb calorimeter) silvery white and shining/polished is to
Minimise its corrosion
Avoid radiation heat loss
Make it look attractive
None of these
✅ The correct answer is option B.
3099. The maximum adiabatic flame temperature in air is __________ the maximum flame temperature in pure oxygen.
Lower than
Higher than
Same as
Not related to
✅ The correct answer is option A.
3066. The main advantage of forced draft over natural draft is that
Combustion of fuel is complete
Smaller height chimney can be used
Furnace control is easier
All of the above
✅ The correct answer is option D.
3073. Which of the following has the highest flame velocity?
H₂
CO
CH₄
C₂H₆
✅ The correct answer is option A.
3078. Junker’s calorimeter is used to determine the calorific value of
Pulverised coal
Gaseous fuels
Fuel oil
None of these
✅ The correct answer is option B.
3081. During combustion of gaseous fuels, deficiency of air
Lengthens the flame
Tends to shorten the flame
Does not affect the flame length
Increases the flame temperature
✅ The correct answer is option A.