d
Isothermal curves have slope which is equal to \(\frac{P}{V}\). It can be calculated as follows \(PV = RT\) Differentiating, \(PdV + VdP = 0\) \(-\frac{dP}{dV} = \frac{P}{V}\) Now, if they cut each other at certain point, they will have different slope at the same point (for same value of \(P\) and \(V\)). So, they can not cut each other at some point. Reason is true, slope is \(\frac{P}{V}\) . For adiabatic curve slope is \(\gamma \) times \(\frac {P}{V}\) .