Electric and Magnetic Fields

At a Glance

For more information

You can visit the Électrium, an EMF interpretation centre in Sainte-Julie, on Montréal's South Shore.


An electromagnetic environment

All around the world, people are constantly exposed to countless man-made sources of electromagnetic waves including cellular telephones, radios, televisions, antennas, satellites, and so on. Found everywhere, these waves have become a normal part of our daily environment. But our environment is also full of electromagnetic radiation from natural sources: light from the Sun carries infrared and ultraviolet radiation, and ionizing radiation comes from the Earth and space. No one can avoid it!

Using electricity

Using electricity adds electric and magnetic fields (EMFs) to this invisible world. Any electric current that flows through a device or a wire-from high-voltage lines to your computer's power cord-generates fields to which we are exposed to varying degrees. However, these fields do not travel like radio waves. In fact, they lose strength rapidly as distance increases.

Electric and magnetic fields

An electric field is not the same thing as a magnetic field. The strength of an electric field depends on electric voltage (measured in volts), whereas the strength of a magnetic field depends on the intensity of the electric current (measured in amperes). In both cases, field strength diminishes with distance from the source.

© Hydro-Québec, 1996-2021. All rights reserved.

Logo Hydro-Québec