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NEET PHYSICSKinetic TheoryMedium

Question

One mole of an ideal monatomic gas undergoes a process described by the equation PV3=constantPV^3 = \text{constant}. The heat capacity of the gas during this process is:

A

3/2 R

B

5/2 R

C

2 R

D

R

Step-by-Step Solution

The molar heat capacity (CC) of an ideal gas undergoing a polytropic process defined by PVn=constantPV^n = \text{constant} is given by the relation derived from the First Law of Thermodynamics (q=ΔUwq = \Delta U - w): C=CV+R1nC = C_V + \frac{R}{1-n}.

  1. Identify the gas type: The gas is monatomic. From the provided data, the molar heat capacity at constant volume for monatomic gases (like Helium, Argon) is approximately 12.5 J mol1 K112.5 \text{ J mol}^{-1} \text{ K}^{-1}, which corresponds to CV=32RC_V = \frac{3}{2}R .
  2. Identify the process: The given equation is PV3=constantPV^3 = \text{constant}, so the polytropic index n=3n = 3.
  3. Calculate C: C=32R+R13C = \frac{3}{2}R + \frac{R}{1-3} C=32R+R2C = \frac{3}{2}R + \frac{R}{-2} C=32R12R=22R=RC = \frac{3}{2}R - \frac{1}{2}R = \frac{2}{2}R = R.

Exam Context & Concepts Covered

This question aligns with the NEET PHYSICS syllabus, specifically targeting concepts from Kinetic Theory. Mastering this topic is crucial for scoring well in the upcoming medical entrance examinations. Solving conceptually related problems will help you understand the nuances of these concepts and improve your problem-solving speed.

PHYSICSKinetic Theorymonatomicundergoesprocessdescribedequation

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