Updated: Question in GATE 2012 Mechanical Engineering Paper with Solution

June 28, 2012

A question in GATE 2012 Mechanical Engineering Paper with Solution has been updated:

An ideal gas of mass m and temperature T_1 undergoes a reversible isothermal process from an initial pressure to a final pressure . The heat loss during the process is Q. The entropy change $\Delta S$ of the gas is

$mR\ ln \bigg($ $\cfrac{P_1}{P_2} \bigg)$
$mR\ ln \bigg($ $\cfrac{P_2}{P_1} \bigg)$ $- \cfrac{Q}{T_1}$
$mR\ ln \bigg($ $\cfrac{P_2}{P_1} \bigg)$