What are electric fields and magnetic fields?
Electric fields exist wherever there is a charged particle. Magnetic fields are created whenever there is a flow of charged particles. A wire with a voltage applied to it will produce an electric field even if there is no current flowing through it. The size of the electric field depends on the voltage. If a current flows through the wire, it will produce a magnetic field, the higher the current the greater the magnetic field. If the current stops flowing, the magnetic field disappears. This means that an appliance plugged into the mains will generate an electric field around it even if it is switched off. If it is then switched on it will also generate a magnetic field. Both electric and magnetic fields are strongest close to their source and rapidly diminish with distance. Electric fields are measured in Volts per metre, written V/m. The unit of magnetic field strength is the Tesla (T), however one Tesla represents a fairly large magnetic field and so they are usually measured in mic
