What is Wilson line?
  • a) It is an isothermal line, at which the condensation completes
  • b) Saturation line of water is also called Wilson line
  • c) It represents the limiting condition of undercooling at which the condensation begins
  • d) It represents an Isobaric line, at which the condensation commences
Considering metastable expansion to be in effect, the flow of wet steam though a convergent-divergent nozzle shall result in a discharge slightly less than the calculated one.
  • a) True
  • b) False
The sudden expansion of dry saturated steam in the absence of dust, doesn’t lead to condensation until its density is about 8 times that of the saturated vapor of the same pressure.
  • a) True
  • b) False
Calculate the enthalpy drop steam enters a convergent-divergent nozzle atbar and 250°C and leaves at 1 bar. The expansion is to be considered metastable.
  • a) 427031.34 kJ/kg
  • b) 55648.32 kJ/kg
  • c) 323654.25 kJ/kg
  • d) 158469.21 kJ/kg
Steam atbar and 300°C enters a convergent-divergent steam nozzle and leaves at 3 bar. If the expansion of the steam is metastable, calculate the supercooled temperature.
  • a) 165°C
  • b) 143°C
  • c) 154°C
  • d) 120°C
Steam atbar and 300°C enters a convergent-divergent steam nozzle and is discharged at 3 bar. Considering the effects of supersaturation calculate the degree of undercooling.
  • a) 36.65°C
  • b) 45.54°C
  • c) 23.32°C
  • d) 62.87°C
Calculate the degree of supersaturation if steam atbar 250°C is discharged at 2 bar by a convergent-divergent nozzle. Consider metastable steam expansion and negligible inlet velocity.
  • a) 5.65
  • b) 3.11
  • c) 2.15
  • d) 2.36
Steam atbar pressure and 250°C enters a convergent-divergent steam nozzle and leaves at 4 bar. The mass flow rate is 5 kg/s. Calculate the exit area of the nozzle if the expansion is metastable.
  • a) 0.00542187 m2
  • b) 0.0029147 m2
  • c) 0.036521 m2
  • d) 0.003265 m2
What is the value of index of expansion for supersaturated steam. (Pvn=C, n is the index of expansion)
  • a) 1.300
  • b) 1.013
  • c) 1.135
  • d) 1.000
Which of the following statement about metastable expansion of steam through a steam nozzle is FALSE?
  • a) It increases the discharge through the nozzle
  • b) Steam is undercooled to a temperature less than that corresponding to its pressure
  • c) Density of steam is increased
  • d) Exit velocity of the steam is increased
The point on the h-s diagram at which the condensation beings and normal conditions of thermal equilibrium are restored is said to be on _____
  • a) wilson line
  • b) saturation vapor curve
  • c) constant dryness fraction line
  • d) constant pressure line
Which of the following is NOT an effect of supersaturation in steam flowing through a convergent-divergent nozzle?
  • a) Increase in specific volume of steam
  • b) Increase in the entropy of steam
  • c) Improvement in dryness fraction
  • d) Increase in the enthalpy drop
Determine the exit pressure of steam if the steam enters a nozzle atbar and 300°C. At the outlet it is observed that the specific volume of the steam is 0.m3/kg. The expansion of steam is metastable.
  • a) 4 bar
  • b) 3 bar
  • c) 2 bar
  • d) 1 bar
0 h : 0 m : 1 s