MCQOPTIONS

Explore topic-wise MCQs in Thermodynamics.

This section includes 15 Mcqs, each offering curated multiple-choice questions to sharpen your Thermodynamics knowledge and support exam preparation. Choose a topic below to get started.

1.	Water at 250°C, 1000 kPa is brought to saturated vapour in a rigid container. Find the specific heat transfer in this isometric process.
A.	−132 kJ/kg
B.	−232 kJ/kg
C.	−332 kJ/kg
D.	−432 kJ/kg
Answer» B. −232 kJ/kg

2.	Water at 250°C, 1000 kPa is brought to saturated vapour in a piston/cylinder with an isothermal process. Find the specific work.
A.	-38 kJ/kg
B.	-138 kJ/kg
C.	-238 kJ/kg
D.	-338 kJ/kg
Answer» E.

3.	A piston/cylinder has 2kg water at 250°C, 1000 kPa which is now cooled with a constant load on the piston. This isobaric process ends when the water has reached a state of saturated liquid. Find the work.
A.	-363.1 kJ
B.	-463.1 kJ
C.	-563.1 kJ
D.	-663.1 kJ
Answer» C. -563.1 kJ

4.	A cylinder containing R-134a at 150 kPa, 10°C has an initial volume of 20 L. A piston compresses the R-134a in a isothermal, reversible process until it reaches the saturated vapour state. Calculate the required work in the process.
A.	-1.197 kJ
B.	-2.197 kJ
C.	-3.197 kJ
D.	-4.197 kJ
Answer» D. -4.197 kJ

5.	A piston cylinder has R-134a at 100 kPa, –20°C which is compressed to 500 kPa in a reversible adiabatic process. Find the specific work.
A.	-41.63 kJ/kg
B.	-11.63 kJ/kg
C.	-21.63 kJ/kg
D.	-31.63 kJ/kg
Answer» E.

6.	A piston/cylinder has 2kg ammonia at 100 kPa, 50°C which is compressed to 1000 kPa. The temperature is assumed to be constant. Find the work for the process assuming it to be reversible.
A.	-727.6 kJ
B.	-794.2 kJ
C.	-723.6 kJ
D.	-743.2 kJ
Answer» B. -794.2 kJ

7.	1kg of water at 300°C expands against a piston in a cylinder until it reaches 100 kPa, at which point the water has a quality of 90.2%. The expansion is reversible and adiabatic. How much work is done by the water?
A.	371.2 kJ
B.	471.2 kJ
C.	571.2 kJ
D.	671.2 kJ
Answer» C. 571.2 kJ

8.	Compression and heat transfer brings R-134a from 50°C, 500 kPa to saturated vapour in an isothermal process. Find the specific work.
A.	-24.25 kJ/kg
B.	-25.25 kJ/kg
C.	-26.25 kJ/kg
D.	-27.25 kJ/kg
Answer» D. -27.25 kJ/kg

9.	An insulated cylinder fitted with a piston contains 0.1 kg of water at 100°C and 90% quality. The piston is moved, compressing the water till it reaches a pressure of 1.2 MPa. How much work is required in the process?
A.	-27.5 kJ
B.	-47.5 kJ
C.	-17.5 kJ
D.	-37.5 kJ
Answer» E.

10.	A cylinder-piston contains ammonia at 50°C, 20% quality, volume being 1 L. The ammonia expands slowly, and heat is transferred to maintain a constant temperature. The process continues until all liquid is gone. Determine the work for this process.
A.	7.11 kJ
B.	9.11 kJ
C.	5.11 kJ
D.	8.11 kJ
Answer» B. 9.11 kJ

11.	1kg of ammonia in a piston/cylinder at 50°C, 1000 kPa is expanded in a reversible adiabatic process to 100 kPa. Find the work for this process.
A.	222.4 kJ
B.	232.4 kJ
C.	242.4 kJ
D.	252.4 kJ
Answer» C. 242.4 kJ

12.	1kg of ammonia in a piston/cylinder at 50°C, 1000 kPa is expanded in a reversible isobaric process to 140°C. Find the work in the process.
A.	50.5 kJ
B.	60.5 kJ
C.	70.5 kJ
D.	80.5 kJ
Answer» B. 60.5 kJ

13.	1kg of ammonia in a piston/cylinder at 50°C, 1000 kPa is expanded in a reversible isothermal process to 100 kPa. Find the work for this process.
A.	333.75 kJ
B.	343.75 kJ
C.	353.75 kJ
D.	363.75 kJ
Answer» E.

14.	In a Carnot-cycle heat pump, heat is rejected from R-22 at 40°C, during which the R-22 changes from saturated vapor to saturated liquid. The heat is transferred to the R-22 at 0°C. Determine the COP for the cycle.
A.	6.83
B.	7.83
C.	8.83
D.	9.83
Answer» C. 8.83

15.	Hot air at 1500 K expands in a polytropic process to a volume 6 times as large with n = 1.5. Find the specific boundary work.
A.	309.5 kJ/kg
B.	409.5 kJ/kg
C.	509.5 kJ/kg
D.	609.5 kJ/kg
Answer» D. 609.5 kJ/kg