Heat does not spontaneously flow from a colder body to a hotter one. Which of the following thermodynamics law states this?

Mechanical Engineering : Engineering Thermodynamics - Quiz(MCQ)

Zeroth law of thermodynamics

First law of thermodynamics

Second law of thermodynamics

Third law of thermodynamics

Correct Answer : Option (C) : Second law of thermodynamics

Explanation : The concept of entropy as a physical attribute of a thermodynamic system is established by the second law of thermodynamics. Despite following the necessity of energy conservation as specified in the first law of thermodynamics, entropy predicts the direction of spontaneous processes and determines whether they are irreversible or impossible.

Recently Updated in Engineering Thermodynamics Questions

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

increases

decreases

remains the same

None of the above

Correct Answer : increases

Explanation : We know that increase in internal energy causes more random motion.

The entropy change of a system between two identifiable equilibrium state is ___ when the intervening process is reversible or change of state is irreversible.

same

different

depends on the process

None of the above

Correct Answer : same

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

heat or thermal energy

heat from combustion of fossil fuel

heat from nuclear fission or fusion

All of the above

Correct Answer : All of the above