Dispersion of light and electromagnetic waves
I can explain what is meant by the visible light spectrum and the spectrum of electromagnetic waves.
Dispersion of light and electromagnetic waves
I can explain what is meant by the visible light spectrum and the spectrum of electromagnetic waves.
Lesson details
Key learning points
- Electromagnetic waves/radiation are transverse oscillations (ripples) in electric and magnetic fields.
- The visible spectrum shows the range of different frequencies (colours) of visible light waves (visible EM radiation).
- In the visible spectrum, violet light has the highest frequency and refracts more than red.
- The EM spectrum shows the range of frequencies that EM waves can have (radio, microwave, IR, visible, UV, X-ray, gamma).
- EM waves in different frequency ranges have the same speed in air, but interact differently with different materials.
Common misconception
The different 'kinds' of EM radiation are different phenomena to each other and to visible light. Pupils may also think all radiation is dangerous, none is natural and that light is not radiation.
Each 'kind' of EM radiation is the same phenomena as light (i.e. waves/ripples in electric and magnetic fields) just with different frequencies and wavelengths. Try to refer to different frequencies/frequency ranges rather than different 'kinds'.
Keywords
Electromagnetic wave - Electromagnetic waves are oscillations/ripples in electric and magnetic fields.
Frequency - The frequency of a wave gives the number of oscillations that occur per second.
Spectrum - A spectrum is a continuous range or scale.
Refraction - Refraction is when waves enter a new material and change direction.
Radiation - Anything that is emitted (given out) from a system and transfers energy away from that system can be called radiation.
Licence
This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).
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