OCR GCSE Physics B key terms

Radiation with enough energy to remove electrons from atoms, producing charged particles called ions.

Exposure to radiation emitted by a source, without radioactive material necessarily being transferred.

Nuclei of the same element that contain the same number of protons but different numbers of neutrons.

A systematic set of rules for naming chemical substances so that their identities can be communicated unambiguously.

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

The unit of energy, with symbol J.

The unit of energy and work done; one joule is equal to one newton metre.

A point where a circuit divides into branches or branches rejoin.

The energy transferred by a device operating at a power of one kilowatt for one hour. $1\text{ kWh} = 3.6\times10^6\text{ J}$.

The energy an object or particle has because it is moving.

Energy stored by an object because it is moving.

A light-dependent resistor: a component whose resistance decreases as light intensity increases.

The principle that an induced current produces a magnetic field which opposes the change that caused the current.

A rigid object that turns about a pivot and transmits the rotational effect of a force.

A component whose resistance decreases as the intensity of light falling on it increases.

A device that detects when a card interrupts a beam of light, allowing short time intervals to be measured electronically.

A relationship in which force is proportional to extension, producing a straight force–extension graph through the origin.

A relationship represented by a straight line on a graph; for a component whose I–V line passes through the origin, current is directly proportional to potential difference.

The straight line through a force in the direction in which that force acts.

A line or curve that represents the overall pattern of plotted data rather than joining each point in turn.

The mains conductor that supplies the appliance and has a potential difference of about 230 V from the neutral and earth wires.

A wave in which the disturbance is parallel to the direction in which the wave travels.

A small magnet mounted so that it can turn and align with a magnetic field.

The region around a magnet or current-carrying conductor in which a magnetic material or compass experiences a force.

An imagined line used to represent a magnetic field; its arrow shows the direction in which the north pole of a small compass would point.

A measure of magnetic field strength, represented by $B$ and measured in tesla (T).

One of the two regions of a magnet where its magnetic effect is strongest; every magnet has a north pole and a south pole.