In thermodynamics, a process is called reversible when :

Options

A. surrounding and system changes into each other.
B. there is no boundary between the system and the surroundings.
C. the surroundings are always in equilibrium with system.
D. the system changes into the surroundings spontaneously.

Answer

C

Explanation

During reversible process, the internal equilibrium is disturbed only infinitesimally small and in the limit, it is not disturbed at all. Thus system and surroundings remain in equilibrium