Explore topic-wise MCQs in Thermodynamics.

This section includes 11 Mcqs, each offering curated multiple-choice questions to sharpen your Thermodynamics knowledge and support exam preparation. Choose a topic below to get started.

1.

A piston/cylinder contains air at 100 kPa, 300 K. A reversible polytropic process with n = 1.3 brings the air to 500 K. Any heat transfer if it comes in is from a 325 C reservoir and if it goes out it is to the ambient at 300 K. Find the specific work.

A. -171.3 kJ/kg
B. -181.3 kJ/kg
C. -191.3 kJ/kg
D. -201.3 kJ/kg
Answer» D. -201.3 kJ/kg
2.

A mass of 2 kg ethane gas at 100 C, 500 kPa, undergoes a reversible polytropic expansion with n = 1.3, to a final temperature of 20 C. Find the work done.

A. 43.7 kJ/kg
B. 53.7 kJ/kg
C. 63.7 kJ/kg
D. 73.7 kJ/kg
Answer» E.
3.

A cylinder/piston contains 100L of air at 25 C, 110 kPa. The air is compressed in a reversible polytropic process to a final state of 200 C, 800 kPa. Assume the heat transfer is with the ambient at 25 C. Find the work done by the air.

A. -11.28 kJ
B. -21.28 kJ
C. -31.28 kJ
D. -41.28 kJ
Answer» C. -31.28 kJ
4.

A cylinder/piston contains carbon dioxide at 300 C, 1 MPa with a volume of 200L. The total external force acting on the piston is proportional to V3. This system is allowed to cool to room temperature, 20 C. Find the work.

A. -24.4 kJ
B. -34.4 kJ
C. -44.4 kJ
D. -54.4 kJ
Answer» B. -34.4 kJ
5.

Consider air in a cylinder volume of 0.2 L at 7 MPa, 1800K. It now expands in a reversible polytropic process with exponent, n = 1.5, through a volume ratio of 8:1. Calculate the work for the process.

A. 1.61 kJ
B. 1.71 kJ
C. 1.81 kJ
D. 1.91 kJ
Answer» D. 1.91 kJ
6.

Helium in a piston/cylinder at 20 C, 100 kPa is brought to 400 K in a reversible polytropic process with exponent n = 1.25. Helium can be assumed to be an ideal gas with constant specific heat. Find the specific work.

A. -587.7 kJ/kg
B. -687.7 kJ/kg
C. -787.7 kJ/kg
D. -887.7 kJ/kg
Answer» E.
7.

A cylinder/piston contains 1kg methane gas at 100 kPa, 20 C. The gas is compressed reversibly to a pressure of 800 kPa. Calculate the work required if the process is polytropic, with exponent n = 1.15.

A. -314.5 kJ
B. -414.5 kJ
C. -514.5 kJ
D. -614.5 kJ
Answer» B. -414.5 kJ
8.

A cylinder/piston contains 1kg methane gas at 100 kPa, 20 C. The gas is compressed reversibly to a pressure of 800 kPa. Calculate the work required if the process is isothermal.

A. -216.0 kJ
B. -316.0 kJ
C. -416.0 kJ
D. -516.0 kJ
Answer» C. -416.0 kJ
9.

Neon at 400 kPa, 20 C is brought to 100 C in a polytropic process with n = 1.4. Find the work done.

A. -52.39 kJ/kg
B. -62.39 kJ/kg
C. -72.39 kJ/kg
D. -82.39 kJ/kg
Answer» E.
10.

The piston/cylinder contains carbon dioxide at 300 kPa, with volume of 0.2 m3 and at 100 C. Mass is added at such that the gas compresses with PV^(1.2) = constant to a final temperature of 200 C. Determine the work done during the process.

A. -80.4 kJ
B. -40.4 kJ
C. -60.4 kJ
D. -50.4 kJ
Answer» B. -40.4 kJ
11.

A polytropic process(n = 1) starts with P = 0, V = 0 and ends with P= 600 kPa, V = 0.01 m3. Find the boundary work done.

A. 1 kJ
B. 2 kJ
C. 3 kJ
D. 4 kJ
Answer» D. 4 kJ