Explore topic-wise MCQs in Thermodynamics.

A piston cylinder has 2.5 kg ammonia at -20 C, 50 kPa. It is heated to 50 C at constant pressure from external hot gas at 200 C. Find the total entropy generation.

A hot metal piece is cooled rapidly to 25 C, removing 1000 kJ from the metal. Calculate the change of entropy if energy is absorbed by vaporizing liquid nitrogen at 101.3 kPa pressure.

A hot metal piece is cooled rapidly to 25 C, removing 1000 kJ from the metal. Calculate the change of entropy if energy is absorbed by ice.

A hot metal piece is cooled rapidly to 25 C, removing 1000 kJ from the metal. Calculate the change of entropy if saturated liquid R-22 at 20 C absorbs the energy so that it becomes saturated vapor.

An insulated cylinder/piston contains R-134a at 1 MPa, 50 C, volume of 100 L. The R-134a expands, dropping the pressure in the cylinder to 100 kPa. The R-134a does 190 kJ of work against the piston during this process. Is that possible?

1 kg of air at 300 K is mixed with 1 kg air at 400 K in a constant pressure process at 100 kPa and Q = 0. Find the entropy generation in the process.

It is better to state that the change of state is irreversible, rather than say it is an irreversible process .

Which of the following laws was formulated by Nernst?

A thermodynamic process where no heat is exchanged with the surroundings is

A perfect black body has a unique characteristic feature as

Which of the following is the largest unit of energy?

When heat is imparted to a system,

Which of the following relation is correct?

When work is dissipated into internal energy, what is the change in the disorderly motion of molecules.

This equation is true only for a reversible(quasi-static) process.

Orderly energy can be easily converted into disorderly energy.

The equation dQ=dU+pdV holds good for

The equation dQ=dU+pdW holds good for any process undergone by a closed stationary system.

When the potential gradient is ____, the entropy change of the universe is ____

At equilibrium, the isolated system exists at the peak of the entropy-hill and

A process always occurs in such a direction as to cause an increase in the entropy of the universe.

The second law affixes a quality to energy of a system at any state.

The available energy of a system ___ as its temperature or pressure decreases and approaches that of the surroundings.

The exergy of a fluid at a higher temperature is ___ than that at a lower temperature and ___ as the

Adequate insulation must be provided for high temperature fluids.

The loss of exergy is more when,

A hot gas flowing through a pipeline can be considered as a

For an infinitesimal reversible process at constant pressure,

A piston cylinder contains 0.5 kg of air at 500 kPa and 500 K. The air expands in a process so pressure is linearly decreasing with volume to a final state of 100 kPa and 300 K. Find the work in the process.

A piston cylinder contains air at 600 kPa, 290 K and a volume of 0.01m^3. A constant pressure process gives 54 kJ of work out. Find the final volume of the air.

The proof that work done in all reversible processes is same can be done by violating Kelvin-Planck statement.

The work done by a closed system in a reversible process is always ___ that done in an irreversible process.

Adequate insulation is not that important for low temperature fluids.

If two bodies were allowed to reach thermal equilibrium, one by heat conduction and other by operating a Carnot engine between them and extracting work, the final equilibrium temperatures would be different.

When considering a finite energy source, its working fluid expands,

Energy is said to be degraded each time it flows through a finite temperature difference.

Exergy is lost due to

Whenever heat is transferred through a finite temperature difference, there is always a decrease in the availability of energy so transferred.

The available energy is known as ____ and the unavailable energy is known as ____

The lowest practicable temperature of heat rejected is the

The part of ____ available for conversion is referred to ____

The ____ obtainable from a certain heat input in a cyclic heat engine is called ____

The unavailable energy is the product of the lowest temperature of heat rejection and the change of entropy of system during the process of supplying heat.

Which of the following is an example of low grade energy?

The ___ in entropy in an irreversible change is a measure of the extent to which energy ___ in that change.

If the first law is the conservation of energy, then the second law is called the law of degradation of energy

When a gas is throttled adiabatically from a high to a low pressure,

Which of the following is a type of energy?

The complete conversion of heat into shaft-work is impossible.

At ambient temperature, exergy of the fluid is