Behaviour of Electromagnetic Waves
Radiations and Radiating 14-16
This set of resources from the IOP takes a little while to get your head around but repays the effort handsomely. Teachers new to the profession, teaching outside their specialism or simply wanting to refresh their practise will find much food for thought here. The emphasis is on building a really good understanding of wave behaviour and developing precision in thought and language.
Teaching and Learning Issues 10, “Light spreading Out" links with Physics Narrative 6, “Intensity May Vary on the Journey”. Together they provide a great base for teaching the inverse square law.
Diffraction of Laser Light
Here’s a super resource to introduce your GCSE students to the magic that is interference. The student version of the film is very good but the teacher version is even better because it will enable all teachers to carry out this simple demonstration most effectively themselves. The teacher notes are good too and will further develop the confidence of the teacher carrying out the experiment. Here’s strong evidence that light is a wave, although of course that’s not the end of the story! An extension of this practical where students take measurements and successfully calculate the wavelength of light makes a great taster lesson for prospective A level physics students.
Electron Diffraction Tube
Once your students are happy with the concept of diffraction, use this demonstration at the end of the topic to show them that there’s more to it than meets the eye. This excellent film will help teachers to feel confident enough to set up an electron-ray diffraction tube, and to explain what is going on to their students. What at first sight looks like some rather tame green circles, is actually an introduction to the weird work of quantum physics and it will leave your students wanting to know more.
What is the wave/particle duality
Beware, once you take a look at Minute Physics, you'll be hooked! This very fast moving and very engaging film takes just over one minute to set out all the fundamentals for students, a great way to round off a lesson.
Where on Earth?
This article would be good to base a piece of homework around since it links well to the topic whilst at the same time extending student’s knowledge to new situations. The article should be read (maybe students could download it from the school’s website?) and then used to complete one of the following suggested pieces of work:
• List 10 technical words used in the article and explain what each one means
• Imagine you are a GPS satellite and write a postcard home to planet Earth
• Write a letter to your MP explaining why the UK should help to fund a European satellite navigation system
• Write a 100 word summary of the article
• Re-write the article so that a student in year 8 could understand it
Windows in the Atmosphere
Teachers may find projecting this picture helpful when teaching about how different electromagnetic waves are affected by the atmosphere. It shows graphically which parts of the electromagnetic spectrum can reach Earth from space and there's lots to discuss with students.
The horizontal scale is wavelength rather than frequency but a frequency below 30MHz corresponds to a frequency greater than10m and a frequency above 30GHz corresponds to a wavelength of less than 1cm.
This alternative picture is nice too! http://www.zina-studio.com/img/s4/v9/p253448451-3.jpg
