Electricity

Electric Charge

The flow of electric charge, typically carried by electrons in a circuit.

Current (I)

Measure of the rate of flow of electric charge, measured in amperes (A).

Potential Difference (V)

The energy transferred per coulomb of charge, measured in volts (V).

Resistance (R)

Opposes the flow of current; higher resistance means lower current for a given voltage, measured in ohms (Ω).

Resistor

Component that limits the current in a circuit.

Variable Resistor

Component that allows changes in resistance to control current flow.

Diode

Allows current to flow in one direction only.

Thermistor

A type of resistor whose resistance decreases as temperature increases.

LDR (Light Dependent Resistor)

A resistor that decreases its resistance as light intensity increases.

Ammeter

Instrument used to measure current, connected in series.

Voltmeter

Instrument used to measure potential difference, connected in parallel.

Series Circuit

Circuit where components are connected end-to-end with the same current flowing through all components.

Parallel Circuit

Circuit where components are connected across the same potential difference and current is shared between branches.

Ohmic Conductors

Components that follow Ohm's Law, where current is directly proportional to voltage, resulting in a linear I-V graph.

Filament Lamp

A component that has a curve I-V graph because its resistance increases with temperature.

AC (Alternating Current)

Electric current that periodically reverses direction, like the UK mains electricity at 230 V, 50 Hz.

DC (Direct Current)

Electric current that flows in only one direction, like that from a battery.

National Grid

The network of cables and transformers that distributes electricity across a country.

Power (W)

The rate at which electrical energy is transferred or converted, measured in watts.

Static Electricity

Electricity produced by friction, leading to a charge build-up on insulating materials.

Earthing

Connection of objects to the ground with a conductor to safely discharge excess static charge.