Q. A monoatomic gas is suddenly compressed to $(1/8)^{th}$ of its innitial volume adiabatically. The ratio of its final pressure to the initial pressure is (Given the ratio of the specific heats of the given gas to be 5/3)

A) 32
B) 40/3
C) 24/5
D) 8
Explanation

(a) In an adiabatic process,
$pV^{\gamma} = constant$
$\Rightarrow \ \ \frac{p_{1}}{p_{2}} = \left( \frac{V_{2}}{V_{1}} \right)^{\gamma}$
$\Rightarrow \ \ \frac{p_{1}}{p_{2}} = \left( \frac{1}{8} \right)^{5/3}$
$\Rightarrow \ \ \frac{p_{1}}{p_{2}} = \left( \frac{1}{2^{3}} \right)^{5/3} = \frac{1}{32}$
$\therefore\ \frac{p_{2}}{p_{1}} = 32$

Dr. Abubacker
Reviewed by Dr. Abubacker

Physics Educator & NEET/JEE Specialist

Ph.D. in Physics with 19+ years of teaching experience.

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