Q: For an Isothermal expansion of a perfect gas, the value of ∆P⁄P is equal to
(a) $-\gamma^{\frac{1}{2}} \frac{\Delta V}{V} $
(b) $ -\frac{\Delta V}{V} $
(c) $ – \gamma \frac{\Delta V}{V} $
(d) $ \gamma^2 \frac{\Delta V}{V} $
Ans: (b)
Sol: As , PV = nRT
P ∆ V + V ∆ P = nR∆T = 0 (Since Process is Isothermal ∆T = 0 )
$ \frac{\Delta P}{P} = -\frac{\Delta V}{V} $