Electrical charge and current

Charge

A property of something which experiences a force when placed in an electric field

Electrons

Negatively charged particles that transfer energy through wires

Current

The rate of flow of electric charge (electrons) around a circuit

Ammeter

A device used to measure current through a component (must be placed in series with that component)

Direct current (dc)

An electric current which flows consistently in one direction around a circuit

Alternating current (ac)

An electric current that continually reverses direction and changes size

Q = It

The equation linking charge flow, current and time

Q

The symbol for charge flow

I

The symbol for current

t

The symbol for time

Amps/amperes (A)

The SI unit for current

Coulombs (C)

The SI unit for charge flow

Seconds (s)

The SI unit for time