## Book: HC Verma - Concepts of Physics Part 2

### Chapter: 27. Specific Heat Capacities of Gases

#### Subject: Physics - Class 12th

##### Q. No. 23 of Exercises

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23
##### Three samples A, B and C of the same gas (γ = 1.5) have equal volumes and temperatures. The volume of each sample is doubled, the process being isothermal for A, adiabatic for B and isobaric for C. If the final pressure is equal for the three samples, find the ratio of the initial pressures.

Let VA, VB, VC be the volume of three gases and TA, TB, TCbe the temperature of A, B, C gas

Given, TA=TB=TC, VA=VB=VC

Here A is undergoing an isothermal process, where V1= VA, V2=2VA

Let P1 and P2 be the initial and final pressures,

Then,

PVγ = const, where V1= VB, V2=2VB

Let P1 and P2 be the initial and final pressures,

I.e.

Here C is isobaric ,the pressure remains constant and equal to

Now, as the final pressures are equal for all the gases

, ratio of the initial pressures

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