$11\mathrm{.}9$ A single phase, $240/120$ V transformer has the following parameters: R$1=1$Ohm; R$2=0\mathrm{.}3$Ohm; X$1=6$ Ohms; X$2=2$ Ohms; Ro $=500$ Ohms; Xo $=1\mathrm{.}5$ kOhms. A load of $10$ Ohms at $0\mathrm{.}8$ power factor lagging is connected across the low$-$voltage terminals of the transformer. The voltage measured across the load side is $110$ V$.$ Compute the following: a$)$ Load voltage referred to the primary side b$)$ Currents of the primary and secondary winding c$)$ Source voltage d$)$ Voltage regulation e$)$ Load power f$)$ Efficiency of the transformer