Physics Circle home Student Login

Home›Chapters›Thermodynamics PYQs›Specific Heats of Gases - Cp, Cv, γ & Mayer's Relation›Question 12

JEE Main 2025 (2 Apr, Shift 1) · Specific Heats of Gases - Cp, Cv, γ & Mayer's Relation

Specific Heats of Gases - Cp, Cv, γ & Mayer's Relation question from JEE Main 2025 (2 Apr, Shift 1)

Q12JEE Main 2025 · 2 APR · SHIFT 1Medium

Specific Heats of Gases - Cp, Cv, γ & Mayer's Relation

γA\gamma_A is the specific heat ratio of monoatomic gas A having 3 translational degrees of freedom. γB\gamma_B is the specific heat ratio of polyatomic gas BB having 3 translational, 3 rotational degrees of freedom and 1 vibrational mode. If γAγB=(1+1n)\frac{\gamma_A}{\gamma_B} = \left(1 + \frac{1}{n}\right), then the value of nn is ________.

Numerical answer type. Work it out, then open the answer.

Show answer and solution

Answer: 3

  1. Gas A (monoatomic): γA=53\gamma_A = \dfrac{5}{3}.
  2. Gas B: CV=3R+R=4RC_V = 3R + R = 4R, CP=5RC_P = 5R, γB=54\gamma_B = \dfrac{5}{4}.
  3. γAγB=53×45=43=1+13\dfrac{\gamma_A}{\gamma_B} = \dfrac{5}{3}\times\dfrac{4}{5} = \dfrac{4}{3} = 1 + \dfrac{1}{3}
  4. So n=3n = 3.
Report a mistake

More questions on Specific Heats of Gases - Cp, Cv, γ & Mayer's Relation