IGCSE Physics: Waves Revision Pack

Comprehensive vocabulary flashcards covering the core definitions, wave types, equations, electromagnetic spectrum properties and uses, and sound characteristics from the IGCSE Physics Waves revision materials.

Amplitude

The size of a sound wave, which determines how loud or quiet a sound is.

Wavelength ($\lambda$)

Distance from one point on a wave to the same point on the next wave, e.g. crest to crest.

Frequency ($f$)

Number of waves passing a point each second, measured in hertz ($\text{Hz}$).

Time period ($T$)

Time taken for one complete wave to pass a point, measured in seconds ($\text{s}$).

Wavefront

A line joining points on a wave that are in step, e.g. all along one crest.

Transverse wave / transverse / Transverse / transverse wave

A wave in which the oscillations are perpendicular (at $90^\circ$) to the direction of energy transfer (e.g., all electromagnetic waves, water waves, waves on a string).

Longitudinal wave

A wave in which the oscillations are parallel to the direction of energy transfer (e.g., sound).

Compressions

Regions in a longitudinal wave where the particles are close together.

Rarefactions

Regions in a longitudinal wave where the particles are spread out.

Energy transfer in waves

Waves transfer energy and information without transferring matter.

Wave speed equation

$v = f \times \lambda$, where $v$ is wave speed in $\text{m/s}$, $f$ is frequency in $\text{Hz}$, and $\lambda$ is wavelength in $\text{m}$.

Frequency equation

$f = \frac{1}{T}$, where $f$ is frequency in $\text{Hz}$ and $T$ is time period in seconds ($\text{s}$).

Doppler effect

The observed change in frequency and wavelength when a wave source moves relative to an observer; moving towards causes a shorter wavelength and higher frequency, while moving away causes a longer wavelength and lower frequency.

Properties of electromagnetic waves

All electromagnetic waves are transverse, can travel through a vacuum, and travel at the same speed of $3.0 \times 10^8\,\text{m/s}$ in a vacuum.

Radio waves

Electromagnetic waves used for broadcasting and communications, with no harmful effects listed in the specification.

Microwaves

Electromagnetic waves used for cooking, satellite transmissions, and mobile phones; harmful effect is internal heating of body cells.

Infrared

Electromagnetic waves used for heaters, night vision, thermal imaging, and remote controls; harmful effect is skin burns.

Visible light

Electromagnetic waves used for optical fibres and photography, with no harmful effects listed in the specification.

Ultraviolet

Electromagnetic waves used for fluorescent lamps and security marking; harmful effect is damage to surface cells and eyes, leading to skin cancer and eye conditions.

X-rays

Electromagnetic waves used for observing the internal structure of objects and medical X-rays; harmful effect is cell mutation leading to cancer.

Gamma rays

Electromagnetic waves used for sterilising food and medical equipment, and killing cancer cells; harmful effect is cell mutation leading to cancer.

Human hearing range

The range of audible sound frequencies for humans, spanning from $20\,\text{Hz}$ to $20\,000\,\text{Hz}$ ($20\,\text{kHz}$).

Pitch

The property of sound that depends on its frequency, with higher or lower sounds depending on the frequency

Loudness

The perceived volume of a sound that depends directly on its amplitude (larger amplitude corresponds to louder sound).