1. The schematic illustrates a conventional ammeter shunt circuit configuration. This is the basic principle behind the operation of the meter. Of course, modern ammeter shunts are a bit more complex.

The ammeter shows the current to be nought point nought six amps. Watch what happens when I add another bulb. ... In this diagram the potential difference produced by the battery is 6 V.

The diagram shows a circuit with two bulbs in parallel. A parallel circuit showing two bulbs, a switch and a cell. An ammeter takes readings near the cell.