GCSE Combined Science Trilogy Physics: Electricity Essentials

Vocabulary flashcards covering the essentials of electricity, including circuit components, mains electricity, the national grid, and static electricity.

Potential difference

A measure of the amount of energy transferred between two points in a circuit; measured in Volts ($V$).

Voltmeter

A device used to measure potential difference that must be connected in parallel to the component it is measuring.

Current

The rate of flow of charge, carried by delocalised electrons in a circuit; measured in Amps ($A$).

Ammeter

A device used to measure current that is connected in series as part of the circuit loop.

Resistance

A measure of how difficult it is for the current to flow in a circuit, caused by electrons colliding with atoms; measured in Ohms ($\Omega$).

Direct current (d.c)

A type of electricity supply where the current only flows in one direction, typically supplied by cells and batteries.

Alternating current (a.c)

A type of electricity supply where the current repeatedly reverses direction, typical of mains electricity.

Mains electricity (U.K. Properties)

The domestic power supply in the U.K. which has a frequency of $50\,Hz$ and a potential difference of $230\,V$.

Live wire (Brown)

The wire in a plug that carries a potential difference of $230\,V$.

Neutral wire (Blue)

The wire in a plug that completes the circuit and maintains a potential difference of $0\,V$.

Earth Wire (Green and Yellow)

The wire in a plug that provides a route to the ground for current to prevent electric shocks.

Fuse

A safety component containing a thin wire that melts if the current is too high, preventing electrical fires or damage.

Step-up transformer

A device that increases potential difference and decreases current to reduce energy lost due to the heating effect in wires during transport.

Step-down transformer

A device that decreases potential difference to a level that is safe for use in factories and homes.

Series circuit

A circuit where components are connected in a single loop; current remains the same throughout, but potential difference splits.

Parallel circuit

A circuit where components are connected in two or more loops; potential difference remains the same, but current splits.

Diode

A component that allows current to flow in only one direction because it has a very large resistance in the reverse direction.

Variable resistor

A type of resistor where the resistance can be manually adjusted or changed.

Thermistor

A component whose resistance changes in response to changes in temperature.

LDR (Light Dependent Resistor)

A component whose resistance changes in response to the intensity of light.

Electric field

The area around a charged object where another charged object will experience a force; it moves out of positive objects and into negative objects.

Static Electricity

The build-up of charge in an insulating material caused by the transfer of negatively charged electrons.