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The expansion of an ideal gas of mass $m$ at a constant pressure $P$ is given by the straight line $D$. Then the expansion of the same ideal gas of mass $2m$ at a pressure $P/ 2 $ is given by the straight line

$E$
$C$
$B$
$A$
Solution
ideal gas equation
$PV = nRT$
$n =\frac{ m }{ M }$
where
$m =$ weight in grams
$M =$ molecular weight
$PV =\frac{ m }{ M } RT$
$V =\left(\frac{ m }{ P }\right) \frac{ R }{ M } T$
slope of expansion curve is determined by $\left(\frac{m}{P}\right) \frac{R}{M}$
for mass $m$ and pressure $P$ slope
$S _{1}=\left(\frac{ m }{ P }\right) \frac{ R }{ M } \quad$ eq(1)
for mass $2 m$ and pressure $\frac{P}{2}$ slope
$S _{2}=\left(\frac{2 m }{\frac{ p }{2}}\right) \frac{ R }{ M }$
$S _{2}=4\left(\frac{ m }{ P }\right) \frac{ R }{ M } \quad eq (2)$
$\frac{e q(2)}{e q(1)}$
$S _{2}=4 S _{1}$
According to question given
$S _{1}=2$
$SO _{2}=8$