Answer - option (d)
The Electro-Magnetic or EM radiation is classified into types according to the frequency of the wave: these types include, in order of increasing frequency, radio waves, microwaves, infrared radiation, visible light, ultraviolet radiation, X-rays and gamma rays.
| Category | Range of Wavelengths (nm) | Range of Frequencies (Hz) |
| Gamma rays | <1<1 | >3×1017>3×1017 |
| X-rays | 1–101–10 | 3×1016–3×10173×1016–3×1017 |
| Ultraviolet light | 10–40010–400 | 7,5×1014–3×10167,5×1014–3×1016 |
| Visible light | 400–700400–700 | 4,3×1014–7,5×10144,3×1014–7,5×1014 |
| Infrared | 700–105700–105 | 3×1012–4,3×10143×1012–4,3×1014 |
| Microwave | 105–108105–108 | 3×109–3×10123×109–3×1012 |
| Radio waves | >108>108 | <3×109 |
These are some examples of uses of electromagnetic waves :
| Category | Uses |
| gamma rays | used to kill the bacteria in marshmallows and to sterilize medical equipment |
| X-rays | used to image bone structures |
| ultraviolet light | bees can see into the ultraviolet because flowers stand out more clearly at this frequency |
| visible light | used by humans to observe the world |
| infrared | night vision, heat sensors, laser metal cutting |
| microwave | microwave ovens, radar |
| radio waves | radio, television broadcasts |
image source from Wikipedia
