Edexcel GCSE Physics key terms

A person or device that receives an electromagnetic wave.

A component for which current is directly proportional to potential difference, so its current–potential difference graph is a straight line through the origin.

A material that does not transmit light through it.

The point at the centre of a thin lens through which a ray is represented as continuing undeviated.

A thin strand of glass or plastic that guides light, including infrared signals, along its length.

A path around another body maintained by gravitational attraction.

The time taken for an orbiting body to complete one orbit.

The distance from an orbiting object to the centre of the body it orbits.

How fast an object moves along its orbit.

The power of ten that represents the approximate scale of a quantity.

A repeated change back and forth about a central value; in a circuit, current, charge or potential difference can oscillate.

The electrons in an atom's highest occupied electron shell; these are the electrons lost when the positive ions considered here form.

A viewing error caused by observing a scale from an angle rather than directly in line with the reading.

A connection in which components lie on separate branches between the same two points.

A circuit arrangement with separate branches that provide more than one path for current.

The original unstable nucleus in a nuclear change.

A simplified representation in which matter consists of tiny particles; their arrangement and movement are used to explain observable properties.

The speed and direction in which a particle is moving. Gas particles have continually changing velocities because their motion is random and collisions alter their directions.

The SI unit of pressure; one pascal is one newton per square metre.

A radiation's ability to travel through matter before being absorbed or losing enough energy to stop.

An inelastic collision in which the objects join together and move with one common velocity afterwards.

The time taken for one complete wave cycle or oscillation, measured in seconds (s).

An object that produces its own magnetic field and has a north pole and a south pole.

A direction at 90° to a surface; also described as normal to the surface.

The shortest distance from the pivot to the force’s line of action, measured at right angles to it.

A change in which no new substance is formed; the material can recover its original properties if the change is reversed.

A property that can be measured and expressed using a numerical value and a unit.

A sliding component that changes the volume of an enclosed gas when it moves inside a cylinder.