Placement)Exam)-)Basic)Principles)of)Thermodynamics)Sample)Questions)
1. Which of the following statements about ideal gases is incorrect?
(a) For an ideal gas contained in an insulated fixed volume tank, pressure is linearly
proportional to temperature.
(b) The difference between the specific heat at constant pressure, Cp, and the specific heat at
constant volume, Cv, is always equal to the ideal gas contant, i.e. Cp – Cv = R.
(c) For an ideal gas contained in a fixed volume closed tank maintained at constant
temperature, its internal energy increases with pressure.
(d) For a single component ideal gas, its specific entropy (kJ/kg-K) is uniquely determined
provided its pressure and temperature is known.
2. The final pressure at the end of an isentropic compression of air can be calculated if following
are known:
(a) Initial temperature, initial pressure, initial volume
(b) Initial temperature, initial pressure, final volume
(c) Initial temperature, initial pressure, final entropy
(d) Initial temperature, initial pressure, initial internal energy
3. The value of convection heat transfer is larger for gases as compared to liquids.
(a) True (b) False
4. Is Joule-Thomson coefficient positive or negative for an expansion process that results in
cooling?
(a) Positive (b) Negative
5. A simple compressible substance undergoes a reversible isothermal process in which the
pressure increases. The entropy of the substance:
(a) increases (b) decreases (c) remains the same
6. Two ideals gases initially at temperature T and pressure P are mixed isothermally and at
constant pressure. In the mixing process, the total entropy of the mixture:
(a) increases (b) decreases (c) remains the same
