OCR GCSE Physics A key terms

An unbroken range of wavelengths and frequencies, rather than radiation at only a few separate values.

The direction in which positive charge is treated as flowing around a circuit, from the positive terminal to the negative terminal in the external circuit.

A numerical multiplier that expresses the relationship between two units and is used to convert a measurement without changing the quantity represented.

A lens that is thicker in the middle than at its edges and makes parallel rays converge.

Microwave radiation detected from all directions in space, originating in the hot early universe.

The unit of electric charge. One coulomb passes a point each second when the current is one ampere.

The number of events recorded by a detector in a given time, often expressed as counts per second.

A part of a car designed to deform in a collision, increasing the time taken for the car to stop.

The formation of an ordered solid crystal structure from a liquid or solution.

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

A coil of conducting wire through which an electric current can flow.

A wire or other electrical conductor through which electric charge is flowing.

A set of current and potential difference readings that shows how an electrical component behaves.

A graph showing how the current through a circuit element varies with the potential difference across it.

One complete repetition of a wave or vibration.

A device that collects and stores measurements from sensors automatically, often at regular time intervals.

The smaller nuclei formed when a larger nucleus splits.

The nucleus produced after a radioactive nucleus has decayed.

A circuit supplied with current that flows in one direction.

A source that provides a potential difference between positive and negative terminals to drive current around a circuit.

A decrease in speed; the acceleration acts opposite to the direction of motion.

A change in an object's shape or dimensions caused by forces.

Mass per unit volume of a substance.

The vertical distance below the surface of a liquid.

A flexible surface that vibrates in response to sound pressure variations or moves to produce them.

A component that allows substantial current in one direction but very little in the reverse direction.

A magnetic needle free to turn vertically as well as horizontally, so it can follow the local direction of Earth's magnetic field.