Power Engineering 3A1 ch 11 Questions With Complete
Solutions
A 20 m^3 volume of perfect gas, initially at 415C and 4250 kPa,
undergoes two step changes. First, the gas is cooled at constant
volume to a final pressure of 1750 kPa. Second, it is compressed
at a constant temperature to 9235 kPa. Calculate the final
temperature and volume of the gas.
Select one:
A. T2 = 10.3°C, V2 = 3.79 m³
B. T2 = -43.7°C, V2 = 8.57 m³
C. T2 = 138.3°C, V2 = 8.57 m³
D. T2 = 170.9°C, V2 = 9.19 m³
E. T2 = 138.3°C, V2 = 9.19 m³ Correct Answers a
A gas at 1000 kPa gauge pressure and 30°C is transferred from a
cylindrical vessel 1.5 m in diameter and 3 m long to another
cylindrical vessel 2.5 m in diameter and 5 m long. If the new
gauge pressure is 150 kPa, calculate the new temperature. Note:
Assume atmospheric pressure to be 100 kPa for this calculation.
Select one:
A. 350°C
B. 318°C
C. 45.9°C
D. 63.7°C
E. 436°C Correct Answers c
A gas expands adiabatically from 1025 kPa abs to 225 kPa abs,
with an expansion index of 1.42. If its volume increases from
1.5 m³ to 4.05 m³, find the amount of available work performed.
Select one:
, A. 441.02 kJ
B. 883.9 kJ
C. 1281.1 kJ
D. 1491.07 kJ
E. 1632.8 kJ Correct Answers d
A perfect gas at 415°C has its condition changed in the
following two steps. In step #1 the volume remains constant at
20 m³ while the pressure changes from 750 kPa gauge to 250
kPa gauge. In step # 2 the gas is compressed isothermally to a
final pressure of 1750 kPa gauge. Calculate the final volume and
temperature of the gas.
Select one:
A. T2 = 10.3°C, V2 = 3.79 m³
B. T2 = -43.7°C, V2 = 8.57 m³
C. T2 = 138.3°C, V2 = 8.57 m³
D. T2 = 170.9°C, V2 = 9.19 m³
E. T2 = 138.3°C, V2 = 9.19 m³ Correct Answers a
A perfect gas is compressed under conditions of constant
temperature to a volume of 30 m³. If the final pressure of the gas
is 450 kPa gauge and the initial volume was 135 m³, what was
the initial pressure? (Assume atmospheric pressure to be 101.3
kPa)
Select one:
A. 122.5 kPa gauge
B. 21.2 kPa gauge
C. 223.8 kPa gauge
D. 101.3 kPa gauge
E. 124.8 kPa gauge Correct Answers b
Solutions
A 20 m^3 volume of perfect gas, initially at 415C and 4250 kPa,
undergoes two step changes. First, the gas is cooled at constant
volume to a final pressure of 1750 kPa. Second, it is compressed
at a constant temperature to 9235 kPa. Calculate the final
temperature and volume of the gas.
Select one:
A. T2 = 10.3°C, V2 = 3.79 m³
B. T2 = -43.7°C, V2 = 8.57 m³
C. T2 = 138.3°C, V2 = 8.57 m³
D. T2 = 170.9°C, V2 = 9.19 m³
E. T2 = 138.3°C, V2 = 9.19 m³ Correct Answers a
A gas at 1000 kPa gauge pressure and 30°C is transferred from a
cylindrical vessel 1.5 m in diameter and 3 m long to another
cylindrical vessel 2.5 m in diameter and 5 m long. If the new
gauge pressure is 150 kPa, calculate the new temperature. Note:
Assume atmospheric pressure to be 100 kPa for this calculation.
Select one:
A. 350°C
B. 318°C
C. 45.9°C
D. 63.7°C
E. 436°C Correct Answers c
A gas expands adiabatically from 1025 kPa abs to 225 kPa abs,
with an expansion index of 1.42. If its volume increases from
1.5 m³ to 4.05 m³, find the amount of available work performed.
Select one:
, A. 441.02 kJ
B. 883.9 kJ
C. 1281.1 kJ
D. 1491.07 kJ
E. 1632.8 kJ Correct Answers d
A perfect gas at 415°C has its condition changed in the
following two steps. In step #1 the volume remains constant at
20 m³ while the pressure changes from 750 kPa gauge to 250
kPa gauge. In step # 2 the gas is compressed isothermally to a
final pressure of 1750 kPa gauge. Calculate the final volume and
temperature of the gas.
Select one:
A. T2 = 10.3°C, V2 = 3.79 m³
B. T2 = -43.7°C, V2 = 8.57 m³
C. T2 = 138.3°C, V2 = 8.57 m³
D. T2 = 170.9°C, V2 = 9.19 m³
E. T2 = 138.3°C, V2 = 9.19 m³ Correct Answers a
A perfect gas is compressed under conditions of constant
temperature to a volume of 30 m³. If the final pressure of the gas
is 450 kPa gauge and the initial volume was 135 m³, what was
the initial pressure? (Assume atmospheric pressure to be 101.3
kPa)
Select one:
A. 122.5 kPa gauge
B. 21.2 kPa gauge
C. 223.8 kPa gauge
D. 101.3 kPa gauge
E. 124.8 kPa gauge Correct Answers b
