Applications of Electromagnetic Waves

Types of Electromagnetic Waves

Radio waves

In the electromagnetic spectrum, radio waves have the longest wavelength, lowest frequency and lowest energy. They are mainly used for communication, such as television, Bluetooth, and radios.

Oscillations in electrical circuits can produce radio waves.


Microwaves are used for satellite communication. Ovens also use microwaves, however, these microwaves need to be absorbed by water molecules within the food.


Infrared can be used for:

  • Electric heaters
  • Cooking
  • Infrared cameras
  • Motion sensors
  • Thermal imaging

Visible light

The visible light spectrum is the region of the electromagnetic spectrum that the human eye can detect.

Fibre optic cables transmit data via visible light, which travels through glass fibres. The light travels from a source to a receiver, which can then be used by telephones or computers.

The wavelength of visible light is shorter than the wavelength of microwaves and radio waves. So, visible light can carry more information, which makes it more useful in fibre optic cables.

Ultraviolet radiation

Ultraviolet (UV) radiation is a type of radiation that is emitted by the sun and artificial sources (e.g. tanning beds). When exposed to UV through sunlight, your skin can tan or burn. However, if you are exposed to too much UV, it can be very dangerous.

X-rays and gamma rays

Both gamma (γ) rays and X-rays are used in hospitals.

Gamma rays are useful for treating cancers, as the high dosage can kill cancer cells. However, sometimes, healthy cells are also killed. Gamma rays can also be used as a medical tracer because they can be passed throughout the body.

X-rays can be used to identify broken bones, as they do not easily pass through bones.

Dangers of Absorbing Electromagnetic Radiation

High frequencies of electromagnetic waves can be harmful to people and can damage living tissue.

The absorption of ultraviolet radiation, X-rays and γ rays are ionising and they can damage body tissue. This is because they are all higher frequency electromagnetic waves, which carry more energy. This means that they can penetrate the body more easily and deeper than lower frequency waves.

The effect of the damage on the body tissue depends on the type of radiation and the size of the dose.

Sievert (Sv) is a measure of radiation dose. This measures the risk of damage caused by the body’s exposure to radiation. As the absorption is usually less than 1 Sv, we tend to use milliSieverts (mSv).

  • 1 Sv = 1,000 mSv