Question

A thermodynamic system is taken from an initial state $i$ with internal energy $U_i=100J$ to the final state $f$ along two different paths iaf and $ibf$, as schematically shown in the figure. The work done by the system along the paths $af,ib$ and $bf$ are $W_{af}=200J,W_{ib}=50J$ and $W_{bf}=100J$ respectively. The heat supplied to the system along the path iaf, $ib$ and $bf$ are $Q_{\text{iaf}}$, $Q_{\text{ib }}$ and $Q_{\text{bf }}$ respectively. If the internal energy of the system in the state $b$ is $U_b=200J$ and $Q_{\text{iaf }}=500J$, the ratio $Q_{\text{bf}}/Q_{\text{ib}}$ is

Answer 1

Answer: 2

$U_b=200J,$
$U_i=100J$
Process iaf

Process	W(in Joule)	$\Delta U$ ( in Joule )s	Q(in Joule)
ia		0
af		200
Net	300	200	500

$\Rightarrow U_f=400$
Joule Process ibf

Process	W(in Joule)	$\Delta U$ ( in Joule )	Q(in Joule)
ib	100	50	150
bf	200	100	300
Net	300	150	450