Physics T3 2026

Waves transfer___

Energy

Distinguish between mechanical and electromagnetic waves

Mechanical waves need a medium, can be transverse or longitudinal and are caused by particles of a medium oscillating, whereas electromagnetic waves do not need a medium, are always transverse and are caused by oscillations in electrical and magnetic fields.

Compare transverse and longitudinal waves

Both kinds of waves are methods of energy transfer, however, transverse waves have particle movement perpendicular to the direction of propagation of the wave, whereas longitudinal waves have particle movement parallel to the direction of propagation of the wave.

Compare mechanical and electromagnetic waves.

Both kinds of waves are methods of energy transfer, however, mechanical waves require a medium for propagation, whereas electromagnetic waves do not. Also, electromagnetic waves are always transverse, whereas mechanical waves may either be transverse or longitudinal.

3 examples of longitudinal waves

Sound waves, seismic P-waves, compression waves in a spring

3 examples of transverse waves

Electromagnetic waves, vibrations in a string, seismic S-waves

compression, rarefaction, crest, trough, displacement, amplitude, period, frequency, wavelength, and velocity on diagram

Compression

Region where particles are close together in a longitudinal wave

Rarefaction

Region where particles are spread apart in a longitudinal wave

Crest

Highest point of a transverse wave

Trough

Lowest point of a transverse wave

Displacement

Distance of a particle from its equilibrium position

Amplitude

Maximum displacement from the equilibrium position

Period

Time taken for one complete wave cycle

Frequency

Number of complete wave cycles per second

Wavelength

Distance between two consecutive identical points on a wave

Wave velocity

Speed at which a wave travels

Electromagnetic spectrum regions

Radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, gamma rays

Electromagnetic spectrum (longest to shortest wavelength)

Radio → Microwaves → Infrared → Visible → Ultraviolet → X-rays → Gamma rays

Electromagnetic spectrum (lowest to highest frequency)

Radio → Microwaves → Infrared → Visible → Ultraviolet → X-rays → Gamma rays

Electromagnetic spectrum (lowest to highest energy)

Radio → Microwaves → Infrared → Visible → Ultraviolet → X-rays → Gamma rays

The sun is a source of ___

white light

Primary colours of light

Red, Green, Blue (RGB)

Secondary colours of light

Cyan, Magenta, Yellow (CMY)