Question 469: Thermodynamics & KTG

Question

Two moles of helium gas are taken over the cycle $ABCD,$ as shown in the $P$-$T$ diagram.
The work done on the gas in taking it from $D$ to $A$ is :
![](https://imagex.cdn.examgoal.net/OCCqNsnBb6k2TwPFf/mQhrDIhyXBnQsHTFlLVUBSCT93Otu/j3qP3Oow0WPqFIuDe9WRhV/image.png)

Accepted Answer

Work done by the system in the isothermal process
$DA$ is $W = 2.303nRT\,{\log _{10}}{{{P_D}} \over {{P_A}}}$
$ = 2.303 	imes 2R 	imes 300{\log _{10}}{{1 	imes {{10}^5}} \over {2 	imes {{10}^5}}} =  - 414R.$
Therefore work done on the gas is $ + \,414\,R.$

Answer

$+414$ $R$

Answer

$-690$ $R$

Answer

$+690$ $R$

Answer

$-414$ $R$

Thermodynamics & KTG

Two moles of helium gas are taken over the cycle ABCD, as shown in the P-T diagram. The work done on the gas in taking it from D to A is :

Choose the correct answer: