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

Three moles of an ideal monoatomic gas undergo a cyclic process as shown in the figure. The temperatures of the gas in different states marked as $1, 2, 3$ and $4$ are $400 \ K, 700 \ K, 2500 \ K$ and $1100 \ K$ respectively. The work done by the gas during the process $1-2-3-4-1$ is (universal gas constant is $R$): (in $R$)

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

One mole of an ideal monoatomic gas is taken along the path $ABCA$ as shown in the $PV$ diagram. The maximum temperature attained by the gas along the path $BC$ is given by

The pressure $(P)$ versus density $(d)$ graph of an ideal gas is shown in the figure. Choose the correct statement.

An ideal gas of mass $m$ in a state $A$ goes to another state $B$ via three different processes as shown in the figure. If $Q_{1}, Q_{2}$,and $Q_{3}$ denote the heat absorbed by the gas along the three paths,then