An electric current is considered to produce three 'effects'. These are its .
heating effect, .
magnetic effect, and .
chemical effect. The heating effect is made us…e of in water heaters, stoves, incandescent lamps, etc. It is also responsible for energy loss, as supply conductors get warm and lose energy to the surroundings. The magnetic effect is made use of in electromagnets, motors, transformers, etc. The chemical effect is made use of in electrolysis (electroplating), but can also cause galvanic corrosion. Any of these effects can be used to define the unit of electric current, the ampere . Until around 1947, the chemical effect was used -based on the amount of silver deposited on an electrode in a given period of time. Since then, the magnetic effect has been used, with the ampere being defined in terms of the resulting force between parallel conductors. (MORE)