Question

For process $1$,$\Delta U$ is positive, for process $2$, $\Delta U$ is zero and for process $3$, $\Delta U$ is negative. Find the parameters indicating $X$ and $Y$ - axis :

• A. Temperature and volume
• B. Temperature and pressure
• C. No. of moles and pressure
• D. Volume and pressure

Answer 1

The correct option is D Volume and pressure

For process $2$, $\Delta U=0$. It will be isothermal process.
In options (A) and (B), temperature is indicated on $X$-axis. If temperature is shown on $X$-axis, isothermal process cannot be shown as otherwise shown in the question for process 2.
Hence, options (A) and (B) are not correct.
Obviously, option (C) is not correct.
Then, option (D) is correct.