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JEE Main 2025 (Online) 29th January Evening Shift
MCQ (Single Correct Answer)
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JEE Main 2025 (Online) 29th January Evening Shift Physics - Heat and Thermodynamics Question 47 English

A poly-atomic molecule $\left(C_V=3 R, C_P=4 R\right.$, where $R$ is gas constant) goes from phase space point $\mathrm{A}\left(\mathrm{P}_{\mathrm{A}}=10^5 \mathrm{~Pa}, \mathrm{~V}_{\mathrm{A}}=4 \times 10^{-6} \mathrm{~m}^3\right)$ to point $\mathrm{B}\left(\mathrm{P}_{\mathrm{B}}=5 \times 10^4 \mathrm{~Pa}, \mathrm{~V}_{\mathrm{B}}=6 \times 10^{-6} \mathrm{~m}^3\right)$ to point $\mathrm{C}\left(\mathrm{P}_{\mathrm{C}}=10^4\right.$ $\mathrm{Pa}, \mathrm{V}_C=8 \times 10^{-6} \mathrm{~m}^3$ ). A to $B$ is an adiabatic path and $B$ to $C$ is an isothermal path.

The net heat absorbed per unit mole by the system is :

A
$500 \mathrm{R}(\ln 3+\ln 4)$
B
$450 \mathrm{R}(\ln 4-\ln 3)$
C
$500 \mathrm{R} \ln 2$
D
$400 \mathrm{R} \ln 4$
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JEE Main 2025 (Online) 29th January Morning Shift
MCQ (Single Correct Answer)
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The work done in an adiabatic change in an ideal gas depends upon only :

A

change in its pressure

B

change in its temperature

C

change in its specific heat

D

change in its volume

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JEE Main 2025 (Online) 28th January Evening Shift
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The ratio of vapour densities of two gases at the same temperature is $ \frac{4}{25} $, then the ratio of r.m.s. velocities will be :

A

$ \frac{5}{2} $

B

$ \frac{25}{4} $

C

$ \frac{4}{25} $

D

$ \frac{2}{5} $

4
JEE Main 2025 (Online) 28th January Evening Shift
MCQ (Single Correct Answer)
+4
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The kinetic energy of translation of the molecules in 50 g of $ \text{CO}_2 $ gas at 17°C is :

A

4205.5 J

B

3582.7 J

C

3986.3 J

D

4102.8 J

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