Switching electricity on and off
Electricity moves at nearly the speed of light. That's almost 300,000 kilometres (or 7.5 times around the Earth) in just one second. When you switch on an appliance the power is instantly transmitted from the power station to your home.
The rate at which electricity can do work (power) depends on the electrical pressure (voltage) and number of electrons flowing (current).
POWER (WATTS) = VOLTAGE (VOLTS) x CURRENT (AMPS)
Electricity only travels along conductors - substances which allow a flow of electrons. The best conductors are metals such as copper and aluminium. Wires made of these metals are used to carry electricity from one place to another.
The power station is like a giant pump forcing electrons to travel along wires. Like the water in a tap electrons are under pressure in the wires leading to the power points in your home. When you plug in and switch on, a connection is made between the wires in the power point and those leading through the appliance. A flow of electrons takes place around the circuit. Electrical energy is converted to other forms such as heat energy or mechanical energy. Electric current enters an appliance under a pressure of about 240 volts and leaves at a reduced pressure (close to zero volts).
Source :Hands On
Energy Discovery Centre
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