2.1 (g)
Contents
Demonstration 1
Start with a very basic reminder of what the may have seen at IGCSE - diffraction through a metal slit in a ripple tank. This can be extended to show diffraction around an object.
Resources
Analysis
Standard diagrams should be recorded for the pattern of diffraction.
Equipment
Safety
Demonstration 2
The microwave kit can be used to demonstrate diffraction through a gap. The detector can be kept stationary behind one side of the metal plate, whilst the other metal plate is moved to create various slit widths, the aplitude of the resulting diffracted wave can be measured using the detector. At this time, use only one slit.
Resources
Analysis
Equipment
Safety
Demonstration 3
Experimenting with sound waves to observe diffraction can be achieved using ultra sound through a metal slit whilst using a microphone connected to an oscilloscope to detect the waves. Alternatively a recorded sound can be played in one room, moving through the open doorway into the corridor will demonstrate that lower frequency sounds are diffracted more through the large doorway.
