If temperature difference between two bodies in which heat transfer takes place increases, the irreversibility

If temperature difference between two bodies in which heat transfer takes place increases, the irreversibility of the process

Options:

a. increases
b. decreases
c. does not change
d. approaches toward reversibility

Correct Answer: a. increases

Explanation

If the temperature difference between the two bodies approaches zero, the heat transfer process approaches irreversibility. In a reversible heat transfer process the temperature difference is infinitely small. But to transfer a finite amount of heat through an infinitesimal temperature difference, we need infinite time or infinite area. But this is not possible. Actual heat transfer process takes place through an finite temperature difference and these are irreversible. Therefore as temperature difference increases, the irreversibility also increases.