Consider the processes A and B shown in figure. It is possible that

From the graph, we can see that the slope of process B is steeper than that of process A.

Now in an isothermal process, under constant temperature, Pressure(P) x Volume(V) = constant … (i) (according to Boyle’s law)

Differentiating on both sides:

PdV + VdP = 0.

slope = = … (ii)

For an adiabatic process,

PV = constant