# Conversion of A to B is carried out by the following process: $\Delta S(A\rightarrow C)=50eV, \Delta S(C\rightarrow B)=30eV, \Delta S(B\rightarrow D) = 20 eV$, where eV, where eV, is entropy unit, then $\Delta S(A\rightarrow B)$ is

(a) +100 eV
(b) +60 eV
(c) -100 eV
(d) -60 eV

$\Delta S(A\rightarrow C)= S_C-S_A=50eV$
$\Delta S(C\rightarrow B)=S_D-S_C=30eV$
$\Delta S(B\rightarrow D)= S_D -S_B = 20 eV$
$\Delta S(A\rightarrow B) = S_B-S_A =eqn. (1) + eqn. (2) - eqn. (3)$= 50 + 30 -20 = 60 eV