Consider the following conditions for the reversibility of a cycle:
1. The P and T of the working substance must not differ appreciably, from those of the surroundings at any state in the process.
2. All the processes, taking place in the cycle, must be extremely slow.
3. The working parts of the engine must be friction free
Which of the above conditions are correct?
a) 1, 2 and 3 b)1 and 2 only
c) 1 and 3 only d) 2 and 3 only