Which of the curves in the given $P-V$ diagram represents an adiabatic process and an isothermal process,respectively?

The figure given below shows the variation in the internal energy $U$ with volume $V$ of $2.0 \text{ mole}$ of an ideal gas in a cyclic process $abcda$. The temperatures of the gas during the processes $ab$ and $cd$ are $500 \text{ K}$ and $300 \text{ K}$ respectively. The heat absorbed by the gas during the complete process is .... $J$. (Take $R = 8.3 \text{ J/mol-K}$ and $\ln 2 = 0.69$)

The $P-V$ diagram of an ideal gas is as shown. Find the work done by the gas in the $ABCD$ process.

An ideal gas undergoes a cyclic process as shown in the diagram. The net work done by the gas in the cycle is

An ideal gas is taken around the cycle $ABCA$ as shown in the $P-V$ diagram. The work done during the cycle is

In the given thermodynamic process,which of the following statements is correct?