Practicing Success

Target Exam

CUET

Subject

Physics

Chapter

Thermodynamics

Question:

Three samples of the same gas A, B and C (\(\gamma = \frac{3}{2}\)) initially have equal volume. Now the volume of each sample is doubled. The process is adiabatic for A, isobaric for B and isothermal for C. If the final pressures are equal for all the three samples, the ratio of their initial pressures is : 

Options:

\(2\sqrt{2}\) : 2 : 1

\(2\sqrt{2}\) : 1 : 2

\(\sqrt{2}\) : 1 : 2

2 : 1 : \(\sqrt{2}\)

Correct Answer:

\(2\sqrt{2}\) : 1 : 2

Explanation:

Let the initial pressure of the three samples be PA, PB and PC, then :

PAV3/2 = (2V)3/2 P ... (PB = P)

\(\Rightarrow P_A = P*2^{3/2}\)

\(\Rightarrow P_C V = P(2V)\)

\(P_C = 2P\)

PA : P : PC = 23/2 : 1 : 2

  = \(2\sqrt{2}\) : 1 : 2