# NEET Physics Thermodynamics Questions Solved

The volume of air increases by 5% in its adiabatic expansion. The percentage decrease in its pressure will be -

(1) 5%

(2) 6%

(3) 7%

(4) 8%

(3) $P{V}^{\gamma }=K$ or $P\gamma \text{\hspace{0.17em}}{V}^{\gamma -1}dV+dP.\text{\hspace{0.17em}}{V}^{\gamma }=0$

or $\frac{dP}{P}=-\gamma \frac{dV}{V}$ or $\frac{dP}{P}×100=-\gamma \text{\hspace{0.17em}}\left(\frac{dV}{V}×100\right)$

= –1.4 × 5 = 7%

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