Question

Which of the following is/are reversible process (es)?           

1. Isentropic expansion

2. Slow heating of water form a hot source

3. Constant pressure heating of an ideal gas form a constant temperature source

4. Evaporation of a liquid at constant temperature

Select the correct answer using the code given below:

a. 1 only                      b. 1 and 2

c. 2 and 3                    d. 1 and 4