<Tr> <Td> <Ul> <Li> </Li> <Li> </Li> <Li> </Li> </Ul> </Td> </Tr> <Ul> <Li> </Li> <Li> </Li> <Li> </Li> </Ul> <P> An electric current is a flow of electric charge . In electric circuits this charge is often carried by moving electrons in a wire . It can also be carried by ions in an electrolyte, or by both ions and electrons such as in an ionised gas (plasma). </P> <P> The SI unit for measuring an electric current is the ampere, which is the flow of electric charge across a surface at the rate of one coulomb per second . Electric current is measured using a device called an ammeter . </P>

A flow of charge can be caused by ions moving in a