Projects
Episode 312: Preparation for electromagnetic waves topic
Students will have a simple idea of electromagnetic radiation – that there are several types of radiation, similar to light, all of which travel at the same speed in empty space.
These episodes develop this picture. In particular, we start from the assertion that light is a transverse wave. How can we know? To explain this, we need to explore the idea of polarisation.
Episode 314: Electromagnetic waves
Episode 315: Inverse square law
(Note that Episode 314 requires students to present information about different regions of the electromagnetic spectrum. You might wish set this task early in Episode 313.)
Main aims
Students will:
- Know some of the methods by which light can be polarised.
- Be able to predict what will be seen or detected with a combination of filters and different orientations of detectors and transmitters.
- Understand why only transverse waves can be polarised.
- Appreciate that polarisation of light and microwaves tell us that electromagnetic waves are transverse.
- Know the general properties of electromagnetic waves including the order of magnitude of the wavelength of each region and how each is detected.
- Show the inverse square law experimentally and to be able to use it in calculations.
Prior knowledge
Students should know the main sub-divisions of the electromagnetic spectrum.
They should also have studied some basic ideas about waves (how they are produced; reflection and refraction).
They should know the difference between transverse and longitudinal waves.
Where this leads
If students study these episodes before they have dealt with radioactivity, it will help them to understand the nature of gamma radiation, as well as the idea that the intensity of radiation diminishes as it spreads out.
Students will learn much more about light when they study diffraction and interference.
Download Word version of Episode 312 ( 34 KB )
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