An ideal gas undergoes four different processes from the same initial state (figure). Four processes are adiabatic, isothermal, isobaric and isochoric. Out of \(1,\) \(2,\) \(3\) and \(4,\) which one is adiabatic?
 

Consider the \((P-V)\) diagram for an ideal gas shown in the figure.

Out of the following diagrams, which figure represents the \((T-P)\) diagram?

1.		2.
3.		4.

Which of the processes described below are irreversible?
 

Choose the correct alternative/s:

1. (a, b, c)

2. (a, d)

3. (b, c, d)

4. (a, b, d)