A $1000-$MVA, $20-$kV$,60-$Hz$,$ three$-$phase generator has the following reactance and time constant ratings: $=0\mathrm{.}17$ p$.$u$.,=0\mathrm{.}3$ p$.$u$.,=1\mathrm{.}5$ p$.$u$.,=0\mathrm{.}05$ s$,=1\mathrm{.}0$ s$,$ and $=0\mathrm{.}1$ s$.$ If the generator is operating at rated voltage $($assume the phase is zero degrees$)$ when a three$-$phase fault occurs, determine the following: a$)$ The subtransient, transient, and steady$-$state currents. b$)$ The symmetrical fault current after $0\mathrm{.}2$ s have passed. c$)$ The DC offset current after $0\mathrm{.}2$ s have passed. d$)$ The asymmetrical fault current after $0\mathrm{.}2$ s have passed. e$)$ The RMS value of the asymmetrical fault current after $0\mathrm{.}2$ s have passed.