3.2 Electrical Power
Power is rate of which an appliance transfers energy.
Watt is a unit of power (W)
1 kW(Kilowatts) = 1000W
An appliance with a power of 1 watt transfers 1 joule of energy to another form of energy every second.
You can calculate power using P=E/t
- P = power in watts, W
- E = energy in joules, J
- t = time taken( in seconds) for energy transfer
Power is energy per second transferred or supplied, so we can write the efficiency equation in term of power: Efficiency = useful power out/total power in (x100%)