The open$-$circuit characteristic $($occ$)$ for a $3$phase, $195$ MVA, $16$KV$,60$Hz sychronous machine is attached. The short$-$circuit test gives IA $=6000$A at If$=650$A$.$ Neglect the armature resistance, Ra$.$ a$)$ Determine the unsaturated and saturated synchronous reactances: Xs$($unsat$),$ Xs$($sat$).$ b$)$ Find the required If if the synchronous machine is to deliver $180$MVA at rated voltage at a power factor of $0\mathrm{.}85$ lagging