An engine operates by taking a monatomic ideal gas through the cycle shown in the figure. The percentage efficiency of the engine is close to $.......\%$

One mole of an ideal gas is taken from $a$ to $b$ along two paths denoted by the solid and the dashed lines as shown in the graph below. If the work done along the solid line path is $w_s$ and that along the dotted line path is $w_d$,then the integer closest to the ratio $w_d / w_s$ is

$A$ cyclic process $ABCD$ is shown in the given $P-V$ diagram. In the following answer, the one that represents the same process as in the $P-T$ diagram is:

The pressure of an ideal gas varies with volume as $P = \alpha V,$ where $\alpha$ is a constant. One mole of the gas is allowed to undergo expansion such that its volume becomes $m$ times its initial volume. The work done by the gas in the process is

$A$ thermodynamic system is taken from state $A$ to $B$ along $ACB$ and is brought back to $A$ along $BDA$ as shown in the $PV$ diagram. The net work done during the complete cycle is given by the area

In the indicator diagram (shown in the figure),the net amount of work done will be