Thermo Flashcards
A steam-water mixture is initially saturated with a quality of 50 percent when a small amount of heat is added. Assuming the pressure remains constant and the mixture remains saturated, the quality of the mixture will __________; and the temperature of the mixture will __________.
A. increase; increase
B. increase; remain the same
C. remain the same; increase
D. remain the same; remain the same
ANSWER: B.
A liquid is saturated with 0 percent quality. Assuming pressure remains constant, the addition of a small amount of heat will… A. raise the steady-state liquid temperature above the boiling point. B. result in a subcooled liquid. C. result in some of the liquid vaporizing. D. result in a superheated liquid.
ANSWER: C.
A steam-water mixture is initially saturated with a quality of 95 percent when a small amount of heat is added to the mixture. If the mixture remains saturated and pressure remains constant, the temperature of the mixture will __________; and the quality of the mixture will __________. A. increase; remain the same B. increase; increase C. remain the same; remain the same D. remain the same; increase
ANSWER: D.
An open container holds 1.0 lbm of saturated water at standard atmospheric pressure. The addition of 1.0 Btu will… A. raise the temperature of the water by 1°F. B. vaporize a portion of the water. C. increase the density of the water. D. result in 1°F of superheat.
ANSWER: B.
An open container holds 1.0 lbm of saturated water at standard atmospheric pressure. The addition of 4.0 Btu will… A. result in 4°F of superheat. B. vaporize a portion of the water. C. increase the density of the water. D. raise the temperature of the water by 4°F
ANSWER: B.
The temperature of a quantity of water is 212°F. Which one of the following parameters, when paired with the temperature, provides insufficient information to determine whether the water is a saturated liquid rather than a saturated liquid-vapor mixture? A. Enthalpy B. Entropy C. Pressure D. Specific volume
ANSWER: C.
A steam-water mixture is initially saturated with a quality of 50 percent when a small amount of heat is added. If pressure remains constant and the mixture remains saturated, mixture steam quality will __________; and mixture temperature will __________. A. increase; increase B. increase; remain the same C. remain the same; increase D. remain the same; remain the same
ANSWER: A.
Consider a saturated steam-water mixture with a quality of 99 percent. If pressure remains constant and heat is removed from the mixture, the temperature of the mixture will __________; and the quality of the mixture will __________. (Assume the mixture remains saturated.) A. decrease; increase B. decrease; decrease C. remain the same; increase D. remain the same; decrease
ANSWER: D.
Which one of the following will occur if 500 Btu is removed from 1.0 lbm of dry saturated steam at 800 psia? (Assume that pressure does not change.) A. Temperature will decrease. B. Density will decrease. C. Specific volume will decrease. D. Enthalpy will increase.
ANSWER: C.
Which one of the following will decrease if heat is added to a saturated vapor at a constant pressure? A. Density B. Temperature C. Entropy D. Enthalpy
ANSWER: A.
Consider a saturated steam-water mixture with a quality of 79 percent. If pressure remains constant and heat is added to the mixture, the temperature of the mixture will __________; and the quality of the mixture will __________. (Assume the mixture remains saturated.) A. increase; increase B. increase; remain the same C. remain the same; increase D. remain the same; remain the same
C. remain the same; increase
Consider a saturated steam-water mixture at 500°F with a quality of 90 percent. If the pressure of the mixture is decreased with no heat gain or loss, the temperature of the mixture will __________; and the quality of the mixture will __________. (Assume the mixture remains saturated.) A. decrease; decrease B. decrease; increase C. remain the same; decrease D. remain the same; increase
B. decrease; increase
Consider dry saturated steam at 470°F. If the pressure of the steam remains constant while heat is added, steam temperature will __________; and steam quality will __________. A. remain the same; remain the same B. remain the same; increase C. increase; remain the same D. increase; increase
C. increase; remain the same
Consider a sealed vessel containing 1,000 lbm of a saturated steam-water mixture at 500°F. The vessel is perfectly insulated with no heat gain or loss occurring. If a leak near the bottom of the vessel results in a loss of 10 percent of the liquid volume from the vessel, the temperature of the mixture will __________; and the overall quality of the mixture will __________. (Assume the mixture remains saturated.) A. decrease; increase B. decrease; decrease C. remain the same; increase D. remain the same; decrease
A. decrease; increase
Consider 1.0 lbm of dry saturated steam at 200 psia. If pressure does not change, which one of the following will be caused by the addition of 6.0 Btu to the steam? A. The steam will remain saturated at the same temperature. B. The steam will become superheated at the same temperature. C. The steam will remain saturated at a higher temperature. D. The steam will become superheated at a higher temperature.
D. The steam will become superheated at a higher temperature
What is the approximate quality of wet steam leaving a reactor at 530 psig with an enthalpy of 928.9 Btu/lbm? A. 25 percent B. 37 percent C. 63 percent D. 75 percent
C. 63 percent
Which one of the following describes the effect of removing heat from a saturated steam-water mixture that remains in a saturated condition? A. Temperature will increase. B. Temperature will decrease. C. Quality will increase. D. Quality will decrease.
D. Quality will decrease
Which one of the following is the approximate quality of a saturated steam-water mixture at 467°F with an enthalpy of 1,000 Btu/lbm? A. 24 percent B. 27 percent C. 73 percent D. 76 percent
C. 73 percent
The temperature of a saturated steam-water mixture is 467°F. Which one of the following parameter values, when paired with the temperature, provides insufficient information to determine the quality of the mixture? A. Pressure is 499.96 psia. B. Enthalpy is 977.33 Btu/lbm. C. Entropy is 1.17 Btu/lbm -°R. D. Specific volume is 0.817 ft3/lbm.
A. Pressure is 499.96 psia.
Given a reactor operating at 985 psig with a feedwater inlet temperature of 400°F, what is the amount of feedwater subcooling? A. 136.6°F B. 140.6°F C. 144.6°F D. 148.6°F
C. 144.6°F
What effect will occur if heat is removed from water that is in a subcooled condition? A. Temperature of the water will increase. B. Enthalpy of the water will decrease. C. Quality of the water will increase. D. Density of the water will decrease.
B. Enthalpy of the water will decrease.
An open vessel contains 1.0 lbm of water at 206°F and standard atmospheric pressure. Which one of the following will be caused by the addition of 3.0 Btu to the water? A. The water temperature will rise by approximately 3°F. B. Approximately 3 percent of the water mass will vaporize. C. The water density will decrease by approximately 3 percent. D. The water will become superheated by approximately 3°F.
A. The water temperature will rise by approximately 3°F.