An 11 kV, three-phase, 50 Hz line of resistance 3 Ω/ph and reactance j7 Ω/ph supplies an 11 kV/400 V transformer having negligible resistance and reactance of j2 Ω/ph referred to 11 kV. The transformer supplies a 400 V feeder of resistance 0.01 Ω/ph and reactance j0.005 Ω/ph. If VR, the receiving-end voltage, is 400 V, calculate VS, the sending-end voltage, when the three-phase load delivered is 250 kW at unity power factor.