QUESTION 1 (13 Marks) Three identical coils are connected in delta to a 200 V, 3-ph supply and each takes 500 W. The power factor is 0.8 lagging. Calculate phase and line currents, and total power when the same Compare the two powers, of both star and delta connection, and coils are connected in star. make a comment. QUESTION 2 (12 Marks) P = IV A resistance pf 20 ohm, inductance of 0.2 H and capacitance of 150 µF are connected in series and are fed from 230 V, 50 Hz supply. Calculate (a) power factor (b) active power (c) reactive power (4) (4) QUESTION 3 (25 Marks) A factory has following loads connected to the mains supply of 415 V, 50 Hz: Load 1: 40 kVA, 0.75 lagging p.f. Load 2: 5 kVA, unity p.f. (a) Find the capacitance needed to correct the power factor of the factory to 0.95 lagging (18) (b) If the Power Utility's minimum power factor is 0.95, calculate the annual penalty fee. (7) (penalty rate is P20/kW/month)

A single-phase AC motor is connected to a 550-V, 50-Hz supply. A clamp-on ammeter indicates the motor has a current draw of 25 A at full load. A wattmeter connected to the motor indicates a true power of 10 kW.  How much capacitance is needed to correct the power factor to 99%?

A single phase AC motor draws 4.5 A from 220 V electricity. Three various power of the motor from the mains is 720 W. a) Calculation of the power factor of the engine. b) Calculating the Capacitance (C) and Power of the capacitor required to make the power coefficient of the motor 0,95