In electronics, current refers to the flow of electric charge through a conductor, such as a copper wire. It is measured in amperes (A) and represents the quantity of electrons flowing past a point in a circuit over a given time. An ampere is the international unit used for measuring current, and it expresses the quantity of electrons flowing past a point in a circuit over a given time. A current of 1 ampere means that 1 coulomb of electrons is moving past a single point in a circuit in 1 second. The calculation is similar to measuring water flow: how many gallons pass a single point in a pipe in 1 minute (gallons per minute, or GPM) .
Current can be direct current (DC) or alternating current (AC) . DC flows in one direction, while AC changes direction periodically. The flow of current is affected by the voltage and resistance in a circuit, as described by Ohms Law. To measure current, an instrument such as a digital multimeter can be used. Current can also be measured using a current clamp accessory, which measures current by gauging the strength of the magnetic field around a conductor.
