Sound and Light

What Sound and Light covers

Sound and Light is examined in Unit A2 4, Sound and Light — examined, one of three optional units (Single Award takes one, Double Award two). It covers transverse and longitudinal waves and wave graphs, phase difference and the electromagnetic spectrum, outer, middle and inner ear, sound intensity and the decibel scale, standing waves, harmonics and resonance tubes, hearing response, phons and equal loudness curves, structure of the eye, rods and cones, accommodation, lens power and correcting long sight, total internal reflection and fibre-optic communication, dipole antennas, wireless networks and radar and attenuation of radio waves and the Doppler effect.

The 11 subtopics

Each one has its own page.

• Transverse and longitudinal waves and wave graphsTransverse and longitudinal waves, compressions and rarefactions, displacement–distance and displacement–time graphs, period and frequency, and wave equation calculations.Open →
• Phase difference and the electromagnetic spectrumPhase difference, in phase and antiphase with worked examples, the electromagnetic spectrum and its shared features, visible wavelengths, a frequency calculation, and why ultraviolet is harmful.Open →
• Outer, middle and inner earThe pinna, auditory canal and eardrum, the ossicles and pressure gain, the Eustachian tube, the oval window, how the cochlea detects frequency, the auditory nerve, semicircular canals and hearing damage.Open →
• Sound intensity and the decibel scaleSound intensity and the threshold of hearing, the decibel equation with worked levels, why a logarithmic scale is used, the threshold of pain, and the inverse square law.Open →
• Standing waves, harmonics and resonance tubesForming standing waves on strings and in air, nodes and antinodes, harmonics on strings and in closed pipes, worked wavelengths, and measuring the speed of sound with a resonance tube.Open →
• Hearing response, phons and equal loudness curvesFinding the most sensitive frequency, ear canal resonance, the audible range, the threshold of hearing curve, phons and equal loudness curves, and how hearing aids use the ear's response.Open →
• Structure of the eye, rods and conesThe cornea, lens, iris, pupil and ciliary muscles, the retina, fovea and blind spot, the humours, rods and cones, colour in dim light and stereoscopic vision.Open →
• Accommodation, lens power and correcting long sightAccommodation for near and distant objects, lens power and the lens equation with worked values, the eye model, the near point, correcting long and short sight, and presbyopia.Open →
• Total internal reflection and fibre-optic communicationThe conditions for total internal reflection, semi-circular block experiments, critical angle and refractive index calculations, fibre construction, single mode and multimode fibres, and modal dispersion.Open →
• Dipole antennas, wireless networks and radarTransmitting and receiving dipoles, half-wave dipole length with a worked value, carrying information by radio, wi-fi and Bluetooth, radar pulses and echo timing, and microwave frequencies.Open →
• Attenuation of radio waves and the Doppler effectAttenuation, free space and path loss with worked intensities, walls and wi-fi, the Doppler effect for sirens with worked frequencies, radar speed guns and Doppler ultrasound.Open →

What you need to know

Answer each one before you reveal it.

Take Sound and Light further

The same content, four other ways.

Commonly confused

Pairs that lose marks when they are blurred together.

• Transverse wave vs Longitudinal wave

  Transverse wave: disturbance whose vibrations are at right angles to the direction of energy transfer. Longitudinal wave: disturbance whose vibrations are parallel to the direction of energy transfer.

• Node vs Antinode

  Node: point of zero amplitude on a stationary wave. Antinode: point of maximum amplitude on a stationary wave.

• Rod cell vs Cone cell

  Rod cell: retinal receptor that works in dim light but gives no colour vision. Cone cell: retinal receptor that gives colour vision and fine detail in bright light.

Questions from this topic

Each one with the model answer underneath.

1. 1

   What is the difference between a transverse and a longitudinal wave?

   Model answer

   A transverse wave has vibrations at right angles to the direction of energy transfer. A longitudinal wave has vibrations parallel to that direction.

2. 2

   Give examples of transverse waves.

   Model answer

   Light and all other electromagnetic waves are transverse. Waves on a stretched string and ripples on water are also transverse.

3. 3

   Give examples of longitudinal waves.

   Model answer

   Sound waves and ultrasound are longitudinal. Primary seismic waves and compressions sent along a slinky spring are also longitudinal.

4. 4

   What are compressions and rarefactions?

   Model answer

   Compressions are regions of a longitudinal wave where the particles are pushed close together. Rarefactions are regions where the particles are spread further apart.

5. 5

   How can a slinky spring demonstrate both types of wave?

   Model answer

   A slinky moved from side to side sends a transverse wave along it. A slinky pushed and pulled along its length sends a longitudinal wave.

6. 6

   How are amplitude and wavelength read from a displacement–distance graph?

   Model answer

   The amplitude is the maximum displacement from the equilibrium line to a crest. The wavelength is the distance between two neighbouring crests, or any two neighbouring points in phase.

What is inside Levo

Six ways to work the same material.

Sound and Light revision questions

What does Sound and Light cover in CCEA A-Level Life and Health Sciences?

11 subtopics: transverse and longitudinal waves and wave graphs, phase difference and the electromagnetic spectrum, outer, middle and inner ear, sound intensity and the decibel scale, standing waves, harmonics and resonance tubes, hearing response, phons and equal loudness curves, structure of the eye, rods and cones, accommodation, lens power and correcting long sight, total internal reflection and fibre-optic communication, dipole antennas, wireless networks and radar and attenuation of radio waves and the doppler effect. Each one has its own page with questions and model answers.

How is Sound and Light organised?

By the CCEA 0008 specification, subtopic by subtopic, so it matches the order you are taught it in.