Voltage and Current

What do the electrical terms voltage (measured in volts) and current (measured in amperes, often shortened to amps) mean? Imagine the electric current flowing in a conducting wire to be like cars travelling along a highway. The highway is the wire and the voltage the speed at which the cars move. The current corresponds to the number of cars passing a given point each second.

When a current flows through a wire, electrical energy is converted into other forms of energy, like heat in a heating element, light from the filament of a bulb, or sound from a loudspeaker. The electric current could also be made to produce mechanical energy, which is what happens in an electric motor. A motor is therefore just a generator operating in reverse.

Making your own generator 

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