Question

The figure shows the $P-V$ diagram of a thermodynamic cycle for an ideal gas. Which of the following graphs for the corresponding $P-T$ diagram is correct ?

• A.
• B.
• C.
• D.

Answer 1

The correct option is A

From the plot of $P-V$ graph,
It can be observed that $AB\text{and}CD$ are isochoric processes.
i.e Volume is constant.
$V=$ constant
$\Rightarrow \frac{nRT}{P}=$ constant
Hence, $P$ vs $T$ graphs for $AB\text{and}CD$ are straight lines passing through the origin.

Also, $BC\text{and}DA$ are isobaric processes ($P=$ constant).
Hence, $P$ vs $T$ graphs for $BC\text{and}DA$ are horizontal lines parallel to the temperature axis.


Thus, option (a) is the correct graph.