Example$-4$: In a balanced three phase system, the wye$-$connected load has impedance of $12+$j$18$ Ohms per phase.The line voltage of the generator is Vab$=280$ V rms $($with $0$phase$).$ Ignore line impedances. Determine$($a$)$ The line currents, $,,$ and $($b$)$ The total complex power on the load.Repeat Example $4$ if the line impedance $($per phase$)0\mathrm{.}5$needs to be accounted for.