An unknown load is connected to a standard European household outlet (240 V rms, 50 Hz). Determine the phase angle difference between the voltage and current, and whether the voltage leads or lags the current, if (a) V = 240/243 V rms and I = 3/9 A rms; (b) the power factor of the load is 0.55 lagging; (c) the power factor of the load is 0.685 leading; (d) the capacitive load draws 100 Waverage power and 500 volt-amperes apparent power.