WBJEE 2019 Physics Solved Paper

Since, the whole system is isolated, this means, there is no transfer of heat between the system and the surrounding. Also, the right side container is initially vacuum, so the gas could easily rush there without any resistive force. As the right side container has no temperature. Thus, the temperature of the ideal gas would remain same even if it enters right side chamber. Therefore, final temperature attained at the equilibrium will be T.