Physics key terms

Earthquake waves that travel through the Earth and provide evidence about its internal layers.

A material with electrical conductivity between that of a conductor and an insulator; its conductivity can change greatly with conditions such as temperature.

A circuit arrangement in which components lie on the same single route around the circuit.

A circuit in which components are connected one after another in a single closed loop, so the same current passes through every component.

A region where a particular direct seismic wave from an earthquake is not detected.

Material placed between a radiation source and a person to reduce the radiation reaching the person.

An unintended, very-low-resistance path through which a large current can flow.

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

A declared direction treated as positive so that velocities, accelerations and displacements can be given consistent signs.

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

The digits in a measured or calculated value that communicate its precision, beginning with the first non-zero digit.

A method in which a liquid is evaporated and then condensed so that it can be collected.

A circuit arrangement in which all components lie on one unbranched path.

A word or symbol placed before a unit to multiply it by a stated power of ten, such as kilo ($10^3$) or milli ($10^{-3}$).

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

The internationally standardised system of measurement, including the metre, kilogram and second.

Two complete conducting rings that maintain contact between a rotating coil and an external circuit.

The iron placed inside an electromagnet that becomes magnetised while current flows and readily loses its magnetism when the current is switched off.

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 coil of wire that produces a magnetic field when a current flows through it.

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

A sound wave is a longitudinal disturbance that transfers energy through a material as successive compressions and rarefactions.

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.