## Noise-cancelling AirPod Pro

The recently launched Apple AirPod Pro presents a wonderful opportunity to relate an A-level concept to a real-world example – how noise-cancelling earphones work. Apple’s website explained it in layman terms that seem to make sense. Let your students attempt… Continue Reading

## Phase Difference GeoGebra Apps

I created a series of GeoGebra apps for the JC topics of Waves and Superposition, mainly on the concept of Phase Difference. The sizes of these GeoGebra apps are optimised for embedding into SLS. When I have time, I will… Continue Reading

A very good explanation of standing waves on Chladni plates. Watch out for the 3-Dimensional standing wave at 3’11”.

## Microwave Standing Waves

In the last tutorial, we were talking about the typical wavelength of different categories of electromagnetic waves. To help us remember the typical wavelength of microwaves, I suggest that we familiarise ourselves with a popular science experiment involving stationary microwaves… Continue Reading

## Pressure Variation in Stationary Sound Waves

For sound waves, we learnt that the compressions (position of maximum pressure) and rarefactions (minimum pressure) occur at the equilibrium position of the displacement of particles. This suggests that the pressure would vary the most in a stationary wave at the… Continue Reading

## Single Slit Diffraction using Fingers

This demonstration requires no material other than your own fingers. Hold your index and middle fingers close to each other, leaving a small slit between them about 1 mm in width. Look through the slit into a source of light… Continue Reading

## Measuring Speed of Sound

Measuring the speed of sound can be done using several methods. The following makes use of the understanding of stationary waves in pipes with one closed end. Such a pipe will have a fundamental mode that looks like this: