Assertion : First law of thermodynamics does not forbid flow of heat from lower temperature to higher temperature.
Reason : Heat supplied to a system always equal to the increase in its internal energy.

Options

A. If both assertion and reason are true and the reason is correct explanation of the assertion.
B. If both assertion and reason are true but reason is not the correct explanation of assertion.
C. If assertion is true, but the reason is false.
D. If assertion is false but the reason is true

Answer

B

Explanation

First law of thermodynamics tells only about the conversion of mechanical energy into the heat energy and vice-versa. It does not put any condition as teh why heat cannot flow from lower temperature to higher temperature.
`dQ=dU+dW`
If heat is supplied as such its volume does not change i.e., `dV=0` then whole of the heat energy supplied to the system will increases in its internal energy only.