Electric and Magnetic Fields



Electric and magnetic fields are present everywhere that electricity flows, including your appliances, the wiring in the walls of your home, and power lines.

To help you understand electric and magnetic fields, we have put together answers to some frequently asked questions:

What are electric and magnetic fields?

  • Electric fields occur when there is a difference in voltage. As the voltage increases so does the strength of the electric field. For example, an electric field is present when you plug an electric appliance into an outlet, even if you do not turn it on.
  • Magnetic fields occur when electric current flows. As the current increases so does the strength of the magnetic field. An electric field will exist even when there is no current flowing. Magnetic fields are only present in an electric appliance, for example, when you turn the appliance on.

Where do electric and magnetic fields come from?

  • Electric and magnetic fields can occur naturally or be created. Natural sources of electrical fields are lightning flashes during thunderstorms or even the earth itself. Common areas we create electric fields are televisions, radios, computers, mobile cell phones, microwave ovens, as well as high voltage transmission lines, distribution lines and transformers.

When are electric and magnetic fields present?

  • Electric and magnetic fields are everywhere there is electricity. Anytime we use electricity we expose ourselves to these fields, including when we use household appliances or equipment like stoves, irons, hairdryers, microwaves, computers or televisions.