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%)