Physics · 3.3 Electromagnetic spectrum
EM Spectrum. Explore it.
All electromagnetic waves are transverse and travel at 3×10⁸ m/s in a vacuum. Slide across the spectrum from radio to gamma to see how wavelength falls and frequency rises — along with each band's uses and dangers.
0625 Topic 3.3 — EM spectrum
c = 3×10⁸ m/s · v = fλ
Uses & dangers
Position
Radio
This band
Band
Radio waves
Typical wavelength
> 1 m
Uses
Broadcasting (TV & radio), communications.
Dangers
Low energy — generally safe.
Across the whole spectrum: wavelength decreases ← → frequency & energy increase. All travel at c = 3×10⁸ m/s in a vacuum.
📋 Order & key facts (Cambridge)
- Order (long λ → short λ): radio, microwave, infrared, visible, ultraviolet, X-ray, gamma.
- All are transverse waves; all travel at 3×10⁸ m/s in a vacuum; all obey v = fλ.
- As wavelength decreases, frequency and photon energy increase — and so does the potential harm.
- Visible light is the only band the eye detects (red ~700 nm → violet ~400 nm).
🎯 Syllabus reference (0625)
- 3.3 Electromagnetic spectrum — state the order of the EM spectrum; recall that all EM waves travel at the same speed in a vacuum; describe typical uses and harmful effects of each band; recall c = 3×10⁸ m/s and use v = fλ.