91Ó°ÊÓ

The P-V diagram represents the initial state of a gas, and the vertical line through the dot divides it into regions 1 and 2 as given.

Analyzing the given graph, we can predict the change in the volume of the gas for the given processes. Next, using the relation between work and change in the volume of the gas, we can determine whether the work done by the gas is positive, negative, or zero for the given processes.

Formula:

The work done during process at constant pressure, $W=p\mathrm{Δ}V$ …(¾±)

Where p is the pressure and $\mathrm{Δ}V$is the change in volume.

From the graph, we can infer that the change in the volume when the gas moves up along the vertical line is $\mathrm{Δ}V=0$.

Thus, the work done by the gas using this above condition in equation (i) as follows: w=0

Therefore, the work done by the gas if it moves up along the vertical line is zero.

From the graph, we can infer that the change in the volume when the gas moves up along the vertical line is $\mathrm{Δ}V=0$.

Thus, the work done by the gas using this above condition in equation (i) is as follows: w=o

Therefore, the work done by the gas if the gas moves down along the vertical line is zero.

If the gas moves anywhere in region 1, its volume will decrease and it will undergo compression. Then, the change in volume will be $\mathrm{Δ³Õ}<0$

Thus, the work done by the gas using this above condition in equation (i) is as follows: W<0

Therefore, the work done by the gas is negative if the gas moves anywhere in region 1.

If gas the moves anywhere in region 2, its volume will increase, and it will undergo expansion. Then, the change in volume will be $\mathrm{Δ}V>0$.

Thus, the work done by the gas using this above condition in equation (i) is as follows: W>0

Therefore, the work done by the gas is positive if the gas moves anywhere in region 2.