Electricity

Current

The flow of electrons around a circuit and the flow of charge in a circuit, measured in amperes (A).

Charge

The quantity of electricity carried by an electron, typically measured in coulombs (C).

Potential Difference

The difference in voltage between two points in a circuit, affecting the flow of current.

Resistance

The opposition to current in a circuit, measured in ohms (Ω); higher resistance results in lower current.

Ohm's Law

States that the current through a conductor is directly proportional to the potential difference across it, provided temperature remains constant.

IV Characteristics

A graph showing the relationship between current and voltage for a specific component.

Thermistor

A temperature-dependent resistor that decreases resistance as temperature increases.

LDR (Light Dependant Resistor)

A resistor that decreases resistance as light intensity increases.

Series Circuit

A circuit with no branches, where current is the same throughout and voltage is shared among components.

Parallel Circuit

A circuit with multiple branches, where total current is the sum of currents through each branch, and potential difference is the same across components.

DC (Direct Current)

A steady current flowing in one direction, typically found in batteries.

AC (Alternating Current)

A current that continuously changes direction, commonly used in mains electricity.

Live Wire

The wire that carries the alternating potential difference from the mains supply, typically colored brown.

Neutral Wire

The wire that completes the circuit to the live wire, typically colored blue.

Earth Wire

A safety wire that provides a path to ground to prevent electric shock, typically colored green/yellow.

Power (P)

The rate of energy transfer, represented by the equation P (W) = I (A) x V (V).

Energy Transfer (E)

The total energy transferred to an appliance, represented by the equation E (J) = P (W) x T (s).

National Grid

A system of cables and transformers linking power stations to consumers, ensuring efficient energy transfer.

Sparking

A phenomenon occurring between two objects when there is a large potential difference, causing a current to flow.

Electrical Fields

A region around a charged object where it exerts a force on other charges, stronger as distance decreases.

Zero Error

An error that occurs when measuring equipment does not read zero when it should, offsetting all other measurements.

Filament Lamp

A lamp whose resistance increases as the temperature of the filament increases.

Variable Resistor

A resistor whose resistance can be adjusted, allowing for changes in voltage.

Step Up Transformer

A transformer that increases voltage for efficient long-distance energy transfer.

Step Down Transformer

A transformer that decreases voltage for safe household use.

Static Electricity

Electricity caused by the movement of charge in conductors, demonstrated by phenomena like balloons sticking to walls.