A 10 kVA 1100:120 V single phase transformer has the following circuit parameters referred to the primary.
Rc = 80 k Ohm, Xm = 10 k Ohm, Re = 20 Ohm, Xe = 50 Ohm.
If the secondary load impedance is 5 < 35 degrees Ohm, what is the transformer efficiency when the output voltage is 120V?