The secondary winding of a transformer has a terminal voltage of Vs(t) = 282.8 sin 377t V. The turns ratio of the transformer is 100:200 (a = 0.50). If the secondary current of the transformer is Is(t)= 7.07 sin (377t -36.87°) A, what is the primary current of this transformer? What are its voltage regulation and efficiency? The impedance of this transformer referred to the primary side are R_eq=0.20ohm, X_eq = 0.750ohm, Rc = 300ohm XM= 80ohm