The $P-V$ diagram shows seven curved paths (connected by vertical paths) that can be followed by a gas. Which two of them should be parts of a closed cycle if the net work done by the gas is to be at its maximum value?

$A$ monoatomic ideal gas goes through a cyclic process as shown in the figure. The efficiency of this process is (in $\%$)

An ideal gas is taken through a quasi-static process described by $P = \alpha V^2$,where $\alpha = 5 \text{ atm}/m^6$. The gas is expanded to twice its original volume of $1 \text{ m}^3$. How much work is done by the expanding gas in this process?

$n$ moles of a van der Waals' gas obeying the equation of state $\left(p+\frac{n^2 a}{V^2}\right)(V-n b)=n R T$,where $a$ and $b$ are gas-dependent constants,is made to undergo a cyclic process that is depicted by a rectangle in the $p-V$ diagram as shown below. What is the heat absorbed by the gas in one cycle?

The pressure of a gas changes linearly with volume from $A$ to $B$ as shown in the figure. If no heat is supplied to or extracted from the gas,then the change in the internal energy of the gas will be $............\,J$.

An ideal gas follows the path shown in the figure. The net work done in the whole cycle is