Year 9 Physics Revision - Vocabulary Flashcards

Vocabulary flashcards covering static electricity, circuits, Ohm's law, and sound waves from the lecture notes.

Static electricity

Build‑up of electric charge on an object (via transfer of electrons) that creates forces of attraction or repulsion.

Electron

Negatively charged subatomic particle.

Proton

Positively charged subatomic particle.

Neutron

Subatomic particle with no charge (neutral).

Charge

Property that causes electrical forces; arises from protons and electrons.

Conductor

Material that allows electric charge to flow easily.

Insulator

Material that resists charge flow; helps prevent current.

Static electrical force field

Electric field around a charged object due to static charge.

Voltage

Potential energy per unit charge; energy given to charges moving around a circuit.

Volt

Unit of voltage; symbol V.

Current

Flow of electric charges per second around a circuit; measured in amperes.

Ammeter

Instrument to measure current; connected in series.

Voltmeter

Instrument to measure voltage; connected in parallel.

Multimeter

Instrument that can measure voltage, current, and resistance.

Resistance

Opposition to the flow of current; measured in ohms.

Ohm’s law

Relationship between voltage, current and resistance: V = I × R.

Ohm

Unit of resistance; symbol is Ω.

V = IR

Another way to express Ohm’s law (Voltage equals current times resistance).

RCD (Residual Current Device)

Device that trips if there is leakage to prevent electric shocks.

Fuse

Component that melts when excessive current flows to break the circuit.

Circuit breaker

Device that interrupts current during faults to prevent damage or fire.

Earth circuit

Protective earth path in household wiring for safety.

Light globe (light bulb)

Electrical component that emits light when current passes.

Connecting wire

Conductor used to connect components in a circuit.

Battery

Source of electrical energy providing the circuit’s voltage.

Switch

Device to open or close a circuit.

Resistor

Component that resists current, providing a defined resistance.

Electric circuit

A complete path through which current can flow.

Sound

Vibration that travels as a wave through a medium; produced by vibrating objects.

Longitudinal wave

Wave in which particle displacement is parallel to the direction of travel (sound is longitudinal).

Compression

Region of high pressure in a longitudinal wave.

Rarefaction

Region of low pressure in a longitudinal wave.

Wavelength

Distance between successive crests or troughs of a wave.

Frequency

Number of complete cycles per second; measured in Hertz (Hz).

Amplitude

Maximum displacement from rest position; relates to loudness.

Pitch

Perceived frequency of a sound.

Resonance

Natural frequency of an object; occurs when external force matches that frequency, amplifying vibration.

Speed of sound

Speed at which sound travels through a medium (about 343 m/s in air at room temperature).

Medium

Substance through which a wave travels (air, water, solid).

Transverse wave

Wave where particle displacement is perpendicular to the direction of travel.