One kg of air is subjected to the following processes:
1. Air expands isothermally from 6 bar to 3 bar.
2. Air is compressed to half the volume at constant pressure. .
3. Heat is supplied to air at constant. volume till the pressure becomes three fold
In which of the above processes, the change in entropy will be positive?
a. 1 and 2 b. 2 and 3
c. 1 and 3 d. 1, 2 and 3