Edexcel GCSE Physics key terms

The International System of Units: the internationally agreed system of measurement used in science.

A digit that contributes to the stated precision of a number; counting begins at the first non-zero digit.

A unit belonging to the International System of Units; the SI unit of time is the second (s).

Two continuous rings that maintain electrical contact between a rotating coil and stationary brushes.

A device that transfers energy from sunlight directly to electricity.

The Sun and the natural bodies associated with it, including eight planets, natural satellites, dwarf planets, asteroids and comets.

A long coil made from many turns of insulated current-carrying wire.

A method of using reflected sound pulses to locate an underwater object or measure water depth.

A travelling disturbance caused by vibrations in a material, such as the changing pressure in air.

An object or process that emits an electromagnetic wave.

A charged object that produces an electric field around itself.

A device that provides a potential difference between its terminals, such as a cell or battery.

The pole of a freely suspended magnet that points approximately towards geographic south, labelled S.

A telescope placed beyond Earth’s atmosphere to observe radiation from space.

A sudden discharge of electric charge through the air, producing a brief flash.

The energy needed to raise the temperature of 1 kg of a substance by 1 °C, without changing its state.

The energy transferred when 1 kg of a substance changes state without a change in temperature.

The specific latent heat for a change between the solid and liquid states, such as melting or freezing.

The specific latent heat for a change between the liquid and gas states, such as boiling or condensing.

A pattern of particular wavelengths emitted or absorbed by matter, used to identify shifts in light from a galaxy.

A display of the intensity of electromagnetic radiation at different wavelengths.

Reflection from a smooth surface in which parallel incident rays leave in the same direction.

The distance travelled per unit time, measured in metres per second (m/s).

A ring divided into two halves that swaps a rotating coil’s connections to the external circuit every half-turn.

The force per unit extension of a spring in its linear region, measured in newtons per metre.

A way of writing a number as $a \times 10^n$, where $1 \leq a < 10$ and $n$ is an integer.

A huge, hot body that produces its own light; the Sun is the star in our Solar System.