Key terms & definitions

The rate at which energy is transferred, measured in watts (W).

A measure of how strongly a component or conductor opposes an electric current, measured in ohms (Ω).

Opposition to the flow of electric current through a component.

A pattern of changing current or potential difference that carries information, such as the pattern of a sound wave.

The application of a weak electrical current to a brain area to investigate the response produced.

Energy transferred when electric charges move through a potential difference.

The transfer of energy from a supply to components when an electric current flows.

Energy transfer caused by moving charges when an electric current flows.

Energy transferred when charge flows through a potential difference in a circuit; the work done equals the energy transferred.

Energy transferred to a component when charge flows through it.

Energy transfer by an electric current doing work on a device.

A furnace that uses electrical energy to melt metal, commonly recovered steel scrap, for steelmaking.

A furnace that uses electric arcs to heat and melt metal, widely used to make steel from scrap.

A property of matter that may be positive, negative or neutral; opposite charges attract.

A physical property of matter that can be positive or negative and causes electrical forces between objects.

A property of matter. Moving electrical charge produces an electric current; the amount of charge is measured in coulombs (C).

The movement of electrical charge through a material.

The flow of electrical charge; its size is the rate at which charge passes a point in a circuit.

The flow of electric charge. Conventional current is taken to flow from positive to negative through an external circuit.

A region around a charged object in which another charged object experiences a force.

The direction of the force that would act on a positive test charge placed at a point in an electric field.

A line used to represent the direction and relative strength of an electric field.

The strength of an electric field at a particular position, indicated qualitatively by how closely spaced its field lines are.

A push or pull experienced by an electric charge because it is in an electric field.

The proportion of a country's electricity generated using each energy resource.

A device that uses the force on a current-carrying coil in a magnetic field to produce rotation.

A device that uses the force on a current-carrying conductor in a magnetic field to produce rotation, transferring energy electrically into mechanical movement.

The harmful passage of electric current through the body.

The harmful passage of an electric current through a person’s body.

A system that transmitted electrical signals along wires, allowing messages to travel rapidly over long distances.