Refer to figure given below. Let \(ΔU_1\) and \(ΔU_2\) be the change in internal energy in processes \(A\) and \(B\) respectively, \(ΔQ\) be the net heat given to the system in process \(A + B\) and \(ΔW\) be the net work done by the system in the process \( A + B.\)

For the above figure:

Choose the correct option:

A thermodynamic system undergoes a cyclic process \(ABCDA\) as shown in Fig. The work done by the system in the cycle is: 
             
1. \( P_0 V_0 \)
2. \( 2 P_0 V_0 \)
3. \( \frac{P_0 V_0}{2} \)
4. zero

The quantity of heat required to take a system from \(\mathrm{A}\) to \(\mathrm{C}\) through the process \(\mathrm{ABC}\) is \(20\) cal. The quantity of heat required to go from \(\mathrm{A}\) to \(\mathrm{C}\) directly is: