Physics · Law of equipartition of energy and applications to specific heat capacities of gases

Assertion is always greater than in gases. Reason Work done at constant pressure

Assertion \( C_{P} \) is always greater than \( C_{V} \) in gases. Reason Work done at constant pressure is more than at constant volume.

  • A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion.
  • B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion.
  • C. Assertion is correct but Reason is incorrect.
  • D. Both Assertion and Reason are incorrect.

Step-by-step solution

The assertion is correct: for gases, C_P > C_V because at constant pressure, heat added does external work in addition to increasing internal energy, while at constant volume, no work is done. The reason states that work done at constant pressure is more than at constant volume, which is true (at constant volume, work is zero). This difference in work directly explains why more heat is needed at constant pressure to achieve the same temperature rise, making C_P greater than C_V. Hence, the reason correctly explains the assertion.
Practise more in this unitView MCQsSign up for full question bank