# For an Isothermal expansion of a perfect gas, the value of ∆P⁄P is equal to

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 )

$\frac{\Delta P}{P} = -\frac{\Delta V}{V}$