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MHT CET 2021 (24 Sep, Shift 1) · Degrees of Freedom & Internal Energy

Degrees of Freedom & Internal Energy question from MHT CET 2021 (24 Sep, Shift 1)

Q23MHT CET 2021 · 24 SEP · SHIFT 1Medium

Degrees of Freedom & Internal Energy

Internal energy of n1n_1 moles of hydrogen at temperature 'TT' is equal to internal energy of 'n2n_2' moles of helium at temperature 2T2T, then the ratio n1:n2n_1 : n_2 is

[Degree of freedom of He=3\text{He} = 3, Degree of freedom of H2=5\text{H}_2 = 5]

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Answer: (b)

  1. U=nf2RTU = n\frac{f}{2}RT.
  2. n1⋅52RT=n2⋅32R(2T)n_1 \cdot \frac{5}{2}R T = n_2 \cdot \frac{3}{2}R(2T)
  3. 5n1=6n2⇒n1:n2=6:55n_1 = 6n_2 \Rightarrow n_1 : n_2 = 6 : 5
  4. So the answer is (b) 6:56 : 5.
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