Question

Heat cannot by itself flow from a body at lower temperature to a body at higher temperature is a statement or consequence of
A. Second Law of Thermodynamics
B. Conservation of momentum
C. Conservation of mass
D. First Law of Thermodynamics

Answer 1

Hint:In this case, a problem is based on the Second Law of thermodynamics, we know that work entropy varies with heat exchange and temperature, hence, analyze each & every option given with the scientific approach and check which option seems to be more appropriate for the given situation to present the answer with proper explanation.



Complete answer:
According to the 2nd Law of Thermodynamics, the change in the entropy of the universe, $\Delta {S_{univ}}$ (i.e., system + surrounding) either increases or remains the same in any spontaneous process.
Mathematically, it can be represented as: -
$\Delta {S_{univ}} > 0$
The Second Law gives an idea of the direction of Heat Transfer in any particular process.
Now, if the heat flows from lower temperature to higher temperature, there will be an overall decrease in the entropy which violates the Second Law. Therefore, to avoid an overall decrease in entropy of the universe, heat cannot flow from a body at lower temperature to a body at higher temperature.
Thus, Heat cannot by itself flow from a body at lower temperature to a body at higher temperature is a statement or consequence of the ‘Second Law of Thermodynamics ’.
Hence, the correct option is (A) Second Law of Thermodynamics.



Thus, the correct option is A.



Note:Since this is a multiple-choice question (theory-based), it is essential that given options are analyzed carefully to give a precise explanation. While writing an explanation of this kind of conceptual problem, always keep in mind to provide the exact reasons in support of your explanation.