(e) Distribution zone substation has a fault level (FL) of 400 MVA on the 11 kV bus. An 11 kV feeder with an impedance of (1 + j3) Q2, connected to the substation, supplies a plant with load demand of 5 MVA at 0.8 pf (lagging). (i) A 2 MVAr capacitor bank is used at the substation for reactive power support and is switched at certain times of the day. Calculate the frequency, in Hz, of the transient generated during switching, assuming a nominal power system frequency of 50 Hz.