4 - Current Flow in a Circuit

 

In the circuit below: when the switch is operated and closed, the battery creates a flow of current around the circuit. As the current flows through the lamp, it lights up.

Current is measured in Amperes (amps). The smaller currents in electronic circuits, are usually measured in milliamps (mA). One milliamp is equal to one thousandth of an amp.

1mA = 1/1000 amp

A battery operated LED torch may typically require, or use, 40 milliamps (mA). Higher powered mains devices, such as an electric kettle or fire, can use 8 amps or 8,000mA.

Close the switch, by clicking it.
Notice how the current flows from the top positive (+) side of the battery, to the bottom negative (-) side.