A hose contains 20 lamps of 200 W for each lamp and a
heater of power 1500 W. they are all connected to
supply voltage of 240 volt. Calculate;
(a) The total current when all loads operates at the same time.
(b) Total energy when 10 lamps and the heater they operate for
5 hours.
a. I = (20*200)/(240) + 1500/240.
I = 16.67A + 6.25A = 22.92A.
b. Energy = ((10*0.20kW) + 1.50kW.)*5h = 17.5kWh.