1. An electrical installation is to be power-factor corrected. One large motor has a maximum rating of 125 kW at 0.78 power factor lagging. Calculate the kVAr rating of a capacitor to correct the motor power factor to 0.99 lagging. 2. The electrical supply company rules which decide how much we pay for our electrical energy is called the


(a) account (b) tariff (c) charge (d) bill

3. The demand for electrical energy is almost always much lower during the early hours of the morning than during the day. This is because

(a) of the way the off-peak tariffs are arranged

(b) power stations are shut down at night

(c) electricity costs are very much higher in the early hours of the morning

(d) most consumers are asleep and not using electricity