Electrical charge and current

Describe how ammeters should be connected with components in circuits

Ammeters should always be arranged in series with the component to be measured.

Charge and current

The size of a current is a measure of how much charge flows past a point each second. It is the rate of flow of charge. The unit of charge is the coulomb (C). One ampere, or amp (A), is one coulomb of charge per second. You can calculate charge using the equation: Charge (C) = current (A) X time (s) Q = IT Don't get the units and quantities confused. The units have sensible abbreviations (C for coulombs, A for amps). The symbols for the quantities are not easy to remember (Q stands for charge, I for current)

Electric current

An electric current is the rate of flow of charge. In a metal, electric current is the flow of electrons.

Measuring current

Electric current will flow in a closed circuit when there is a source of potential difference. To measure the size of the current flowing through a component, an ammeter is connected in series with the component.

Describe what happens to the size of the current in a series circuit.

The current is the same value at any point in a series circuit.