Easy MCQ +4 / -1 PYQ · JEE Mains 2024

A diatomic gas $(\gamma=1.4)$ does $200 \mathrm{~J}$ of work when it is expanded isobarically. The heat given to the gas in the process is :

  1. A $800 \mathrm{~J}$
  2. B $600 \mathrm{~J}$
  3. C $700 \mathrm{~J}$ Correct answer
  4. D $850 \mathrm{~J}$

Solution

$\begin{aligned} & \gamma=1+\frac{2}{\mathrm{f}}=1.4 \Rightarrow \frac{2}{\mathrm{f}}=0.4 \\\\ & \Rightarrow \mathrm{f}=5 \\\\ & \mathrm{~W}=\mathrm{nR} \Delta \mathrm{T}=200 \mathrm{~J} \\\\ & \mathrm{Q}=\left(\frac{\mathrm{f}+2}{2}\right) \mathrm{nR} \Delta \mathrm{T} \\\\ & =\frac{7}{2} \times 200=700 \mathrm{~J}\end{aligned}$

About this question

Subject: Physics · Chapter: Thermodynamics · Topic: Thermodynamic Processes

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