Thermodynamics MCQ
SET-2
21. Carbonisation of coal consists of
- A. drying and crushing the coal to a fine powder
- B. moulding the finely ground coal under pressure with or without a binding material
- C. heating the wood with a limited supply of air to temperature not less than 280°C
- D. none of the above
Answer: D
22. The efficiency of Stirling cycle is __________ Carnot cycle.
- A. greater than
- B. less than
- C. equal to
Answer: C
23. According to Gay-Lussac law for a perfect gas, p/T = constant, if v is kept constant.
- A. True
- B. False
Answer: A
24. There is no change in internal energy in an isothermal process.
- A. Correct
- B. Incorrect
Answer: A
25. If the value of n = 0 in the equation pvn = C, then the process is called
- A. constant volume process
- B. adiabatic process
- C. constant pressure process
- D. isothermal process
Answer: C
26. The value of specific heat at constant pressure (cp) is __________ that of at constant volume (cv).
- A. less than
- B. equal to
- C. more than
Answer: C
27. When coal is strongly heated continuously for 42 to 48 hours in the absence of air in a closed vessel, the process is known as __________ of fuel.
- A. atomisation
- B. carbonisation
Answer: B
28. Which of the following is correct?
- A. Absolute pressure = Gauge pressure + Atmospheric pressure
- B. Gauge pressure = Absolute pressure + Atmospheric pressure
- C. Atmospheric pressure = Absolute pressure + Gauge pressure
- D. Absolute pressure = Gauge pressure – Atmospheric pressure
Answer: A
29. The distillation carried out in such a way that the liquid with the lowest boiling point is first evaporated and recondensed, then the liquid with the next higher boiling point is then evaporated and recondensed, and so on until all the available liquid fuels are separately recovered in the sequence of their boiling points. Such a process is called
- A. cracking
- B. carbonisation
- C. fractional distillation
- D. full distillation
Answer: C
30. Which of the following statement is incorrect?
- A. The liquid fuels consist of hydrocarbons.
- B. The liquid fuels have higher calorific value than solid fuels.
- C. The solid fuels have higher calorific value than liquid fuels.
- D. A good fuel should have low ignition point.
Answer: C
31. Which of the following gas is mostly used in town for street and domestic lighting and heating?
- A. Producer gas
- B. Coal gas
- C. Mond gas
- D. Coke oven gas
Answer: B
32. The value of gas constant (R) in S. I. units is
- A. 0.287 J/kgK
- B. 2.87 J/kgK
- C. 28.7 J/kgK
- D. 287 J/kgK
Answer: D
33. In the first law of thermodynamics, the total energy of the system remains constant.
- A. True
- B. False
Answer: A
34. The efficiency of Diesel cycle increases with
- A. decrease in cut-off
- B. increase in cut-off
- C. constant cut-off
- D. none of these
Answer: A
35. Coal gas is obtained by mixing coal and gas at ambient conditions.
- A. Yes
- B. No
Answer: B
36. According to Avogadro’s law, the density of any two gases is __________ their molecular masses, if the gases are at the same temperature and pressure.
- A. equal to
- B. directly proportional to
- C. inversely proportional to
Answer: B
37. The kinetic energy of molecules of a gas becomes zero at absolute zero temperature.
- A. Agree
- B. Disagree
Answer: A
38. One kg of carbon monoxide requires __________ kg of oxygen to produce 11/7 kg of carbon dioxide gas.
- A. All
- B. 4/7
- C. 11/4
- D. 9/7
Answer: B
39. The absolute zero temperature is taken as
- A. -273°C
- B. 273°C
- C. 237°C
- D. -237°C
Answer: A
40. The specific heat of water is
- A. 1.817
- B. 2512
- C. 4.187
- D. none of these
Answer: C