Mechanical Engineering - Heat Transfer, Refrigeration and Air Conditioning - Discussion

The correct answer is: Zeroth law of thermodynamics.

Zeroth's Law of Thermodynamics states;

"If two systems are in thermal equilibrium with a third system, then they are also in thermal equilibrium with each other."

This law describes the fundamental principle of heat transfer, which is the transfer of energy from a system at a higher temperature to a system at a lower temperature until it reaches thermal equilibrium.

The other options are not directly related to the principle of heat transfer:

- First Law of Thermodynamics: Describes the conservation of energy, but not specifically heat transfer.
- Second Law of Thermodynamics: Describes the direction of spontaneous processes, including heat transfer, but not the principle itself.
- Kirchhoff's Law: Relates to electrical circuits, not heat transfer.

The Zeroth Law is often considered the most fundamental law of thermodynamics, as it defines the concept of temperature and thermal equilibrium.

Since, the second law (kelvin and claussius statement) deals with the heat transfer.

Heat transfer takes place according to higher to lower so its second is 100% right here.

Yes, right @Prashant.

Heat transfer takes place from higher to lower temperature according to the second law of thermodynamics.

Second law talks about the direction constraints in energy transaction or in any natural and synthetic processes.

Eg: grey hair can not turn black, but the reverse is true.

- source nptel

kelvin plank and Clausius statements tell us same.

0th law tells about thermal equilibrium.

1st law conservation of all energy not heat transfer.

2nd law makes possible heat flow by giving direction.

Because zeroth is for thermal equilibrium.

Answer C is right.

Answer is C because according to 2nd law it is impossible to transfer heat from low temp reservoir to high i.e. heat transfer is from high to low.