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Question 1. (35 Marks) A big industrial load is connected to a 1.05 pu bus via a feeder. The load takes S = 1.2 pu at 0.85 power factor (lagging), which causes the voltage at the load bus to drop to 0.78 pu. Installation of a reactive power compensation is considered at the load bus. Find the amount of reactive power Qc (in per unit), and the corresponding capacitive susceptance Bc=1/Xc (in per unit), that are needed to keep load bus voltage at 0.95 pu: () by a series capacitor; (ii) by a shunt capacitor. In answering this question, please first use the approximate method (based on formula Q = (AV)*V/X), and then use the accurate method (based on phasor diagrams). Compare the results obtained by the two methods, and conclude on how accurate the approximate method really is. a