List of top Mechanical Engineering Questions on Thermodynamics

The area enclosed by a thermodynamic cycle on a p-v diagram represents:
Compared to the Otto cycle for the same compression ratio, the diesel cycle efficiency is:
Heat conduction through a wall follows:
Conduction requires:
In a vapour compression refrigeration cycle, the refrigerant absorbs heat in the following.
With rise in gas temperature, dynamic viscosity of most of the gases:
Heat transfer takes place according to:
In an open system, both ............. and ............. can cross the boundary?
Reheating in Brayton cycle:
In a throttling process, which one of the parameters remains constant?
A process in which no heat is transferred is called:
Compression ratio of diesel cycle is:
Kelvin-Planck's law deals with:
Brayton cycle is used in:
Control volume refers to a:
Rankine cycle is used in:
Second law introduces the concept of:
Availability is:
Match List I with List II:
LIST I (Component)LIST II (Equipment used in)
A. Draft TubeIII. Francis Turbine
B. Thermostatic Expansion ValveII. Cold Storage
C. Feed Water HeaterI. Thermal Power Plant
D. Automatic Expansion ValveIV. Central AC Plant
Choose the correct answer from the options given below:
Assertion (A): In heating and dehumidification of air, relative humidity of air decreases.
Reason (R): Sensible heating causes enthalpy to decrease.
In light of the above statements, choose the correct answer from the options given below.
In a simple saturated Vapour compression refrigeration cycle, the enthalpy at various state points are: 10 kJ/kg, 45 kJ/kg and 25 kJ/kg. The mass flow rate of refrigerant is 2 kg/s:
  1. The power consumption of compressor is 40 kJ/kg
  2. The refrigeration capacity is 70 kW
  3. The COP is 1.75
  4. Heat rejected in condenser is 110 kW
Choose the correct answer from the options given below.
For the same compression ratio and same heat supplied in Otto, Diesel and Dual cycles:
(A) Otto cycle has maximum efficiency.
(B) Diesel cycle has minimum heat rejected.
(C) Dual cycle has maximum heat rejected.
(D) Diesel cycle has maximum heat rejected.
Choose the correct answer from the options given below.
With increase in pressure ratio in Brayton cycle the net work output
A system at 500 K receives 7200 kJ/min of heat from a source at 1000 K The ambient temperature is 300 K The system and source temperature remain constant during heat transfer The decrease in available energy due to heat transfer through finite temperature difference is
Given below are two statements, one is labelled as Assertion (A) and the other one labelled as Reason (R):
Assertion (A): The Clausius statement of second law of thermodynamics states that it is impossible to transfer heat from a body at low temperature to a body at high temperature without the aid of external work.
Reason (R): Heat always flows from low temperature to high temperature.
In light of the above statements, choose the correct answer from the options given below: