The three-phase transmission line receiving end voltage is rated at 21 kV. A load of 1250 kW is connected at the receiving end of the transmission line, which is 60 km long. The parameters of the transmission line are given by r = 0.09 Ω/km and x = 0.7 Ω/km. If the machine is working at a power factor of 0.85 lagging, determine:
a) The series reactance of the transmission line
b) Sending end line voltage
c) Percentage Voltage regulation
d) Percentage Efficiency