d
$\mathrm{K.V}$ $\mathrm{.L.}$ on left mesh
${2-3 \mathrm{I}_{1}-2 \mathrm{I}_{1}=0} $
${\mathrm{I}_{1}=0.4 \mathrm{\,amp}}$
$\mathrm{K.V.L.}$ on right mesh
$4-3 I_{2}-5 I_{2}=0$
$\mathrm{I}_{2}=0.5 \mathrm{\,amp}$
Potential difference between $A $ and $ B$
${\mathrm{V}_{\mathrm{A}}+3 \mathrm{I}_{1}+4=\mathrm{V}_{\mathrm{B}}} $
${\mathrm{V}_{\mathrm{A}}-\mathrm{V}_{\mathrm{B}}=-3(\mathrm{O} .4)-4=-5.2 \mathrm{\,V}}$
