$2-7.$ A $30-$KVA, $8000/230-$V distribution transformer has an impedance referred to the primary of $20+$ j$100$ N$.$ The components of the excitation branch referred to the primary side are Rc $=100$ kN and Xx $=20$ kn$.($a$)$ If the primary voltage is $7967$ V and the load impedance is $24=2\mathrm{.}0+30\mathrm{.}712,$ what is the secondary voltage of the transformer? What is the voltage regulation of the transformer? $($b$)$ If the load is disconnected and a capacitor of $-$;$3\mathrm{.}02$ is connected in its place, what is the secondary voltage of the transformer? What is its voltage regulation under these conditions?