Easy MCQ +4 / -1 PYQ · JEE Mains 2020

A gas mixture consists of 3 moles of oxygen and 5 moles of argon at temperature T. Assuming the gases to be ideal and the oxygen bond to be rigid, the total internal energy (in units of RT) of the mixture is :

  1. A 11
  2. B 20
  3. C 15 Correct answer
  4. D 13

Solution

U $= {{{f_1}} \over 2}{n_1}RT + {{{f_2}} \over 2}{n_2}RT$ <br><br>$= {5 \over 2}\left( {3RT} \right) + {3 \over 2} \times 5RT$ <br><br>$\therefore$ U $= 15RT$

About this question

Subject: Physics · Chapter: Thermodynamics · Topic: Zeroth and First Law

This question is part of PrepWiser's free JEE Main question bank. 271 more solved questions on Thermodynamics are available — start with the harder ones if your accuracy is >70%.

Drill 25 more like these. Every day. Free.

PrepWiser turns these solved questions into a daily practice loop. Chapter-wise drills, full mocks, AI doubt chat. No auto-renew.

Start free →