Q. The volume of an ideal gas is 1 litre and its pressure is equal to $72cm$ of mercury column. The volume of gas is made $900\ cm^{3}$ by compressing it isothermally. The stress of the gas will be
A) $8\ cm$ (mercury)
B) $7\ cm$ (mercury)
C) $6\ cm$ (mercury)
D) $4\ cm$ (mercury)
Explanation
(a) For isothermal process $P_{1}V_{1} = P_{2}V_{2}$
$\Rightarrow P_{2} = \frac{P_{1}V_{1}}{V_{2}} = \frac{72 \times 1000}{900} = 80\ cm$
Stress $\mathrm{\Delta}P = P_{2} - P_{1} = 80 - 72 = 8cm$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.