Explore topic-wise MCQs in Thermodynamics.

This section includes 3 Mcqs, each offering curated multiple-choice questions to sharpen your Thermodynamics knowledge and support exam preparation. Choose a topic below to get started.

1.

In a cryogenic experiment you need to keep a container at -125 C although it gains 100 W due to heat transfer. What is the smallest motor you would need for a heat pump absorbing heat from the container and rejecting heat to the room at 20 C?

A. 97.84 kW
B. 98.84 kW
C. 99.84 kW
D. 95.84 kW
Answer» B. 98.84 kW
2.

A cyclic machine, as shown below, receives 325 kJ from a 1000 K energy reservoir. It rejects 125 kJ to a 400 K energy reservoir and the cycle produces 200kJ of work as output. Is this cycle reversible, irreversible, or impossible?

A. reversible
B. irreversible
C. impossible
D. none of the mentioned
Answer» D. none of the mentioned
3.

An air-conditioner provides 1 kg/s of air at 15 C cooled from outside atmospheric air at 35 C. Estimate the amount of power needed to operate the air-conditioner.

A. 1.09 kW
B. 1.19 kW
C. 1.29 kW
D. 1.39 kW
Answer» E.