OCR GCSE Physics B key terms

Current that flows in one direction, even if its size varies.

A circuit supplied by a direct potential difference, so conventional current travels in one direction.

An electrical supply that maintains the same polarity, so current in a connected circuit flows in one direction.

The separation of white light into colours because different wavelengths travel at different speeds and refract by different amounts in a material.

The volume of fluid pushed aside by an immersed object.

The straight-line change in position from a starting point, including direction.

Energy transferred in unwanted ways and spread into less useful stores in the surroundings.

The spreading of energy into less useful stores, usually the thermal stores of the surroundings.

The total length of the path travelled by an object, without any direction attached.

A lever arrangement that makes the load move farther or faster than the effort point; this requires a larger effort force.

A graph showing how the total distance travelled by an object changes with time.

A generator with a split-ring commutator that keeps the output at one polarity, producing current in one direction in a complete circuit.

A safety conductor connecting an appliance's metal casing to earth; it normally carries no current but provides a low-resistance path during a fault.

The fraction of the total energy transferred that is transferred usefully.

Deformation that disappears when the forces causing it are removed, so the object returns to its original shape and size.

The greatest load after which a spring will still return to its original length when the load is removed.

Energy stored when an object is stretched or compressed and available to be released as it returns towards its original shape.

An electrical current or potential difference that varies with time to represent information such as sound.

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

A property of matter measured in coulombs (C); moving charge forms an electric current.

The rate at which electric charge passes a point in a circuit, measured in amperes (A).

A region around an electric charge in which another charge experiences a force.

A magnet produced by an electric current, usually using a coil wound around an iron core.

The production of a potential difference across a conductor when the magnetic field through it changes.

The complete continuous range of electromagnetic radiation, grouped according to wavelength or frequency.

A wave that does not require a material medium and can therefore travel through a vacuum; visible light is an example.

A negatively charged subatomic particle that surrounds the nucleus at particular energy levels.