Ncert Exercises & Solutions

The pressure-volume work for an ideal gas can be calculated by using the expression $W = \int_{V_{i}}^{V_{f}} p_{ext} d V$ .

The work can also be calculated from the pV-plot by using the area under the curve within the specified limits.
An ideal gas is compressed (a) reversibly or (b) irreversibly from volume $V_{i}$ to $V_{f}$ .
The correct option is:

1.	$ \mathrm{W} \text { (reversible) }=\mathrm{W} \text { (irreversible) }$
2.	$ \mathrm{W} \text { (reversible) }<\mathrm{W} \text { (irreversible) }$
3.	$ \mathrm{W} \text { (reversible) }>\mathrm{W} \text { (irreversible) }$
4.	$ \mathrm{W} \text { (reversible) }=\mathrm{W} \text { (irreversible) } + \text P_{\text {ext}}.\Delta V$

1.	\( \mathrm{W} \text { (reversible) }=\mathrm{W} \text { (irreversible) }\)
2.	\( \mathrm{W} \text { (reversible) }<\mathrm{W} \text { (irreversible) }\)
3.	\( \mathrm{W} \text { (reversible) }>\mathrm{W} \text { (irreversible) }\)
4.	\( \mathrm{W} \text { (reversible) }=\mathrm{W} \text { (irreversible) } + \text P_{\text {ext}}.\Delta V\)