1 Electric and magnetic fields are present in and around the earth, which has a magnetic field strong enough to make a compass needle point north. This field averages approximately 500 mG at the earth's surface and is relatively static.
Electric and magnetic fields are present in and around the earth, which has a magnetic field strong enough to make a compass needle point north. This field averages approximately 500 mG at the earth's surface and is relatively static.
1 Electric and magnetic fields are present in and around the earth, which has a magnetic field strong enough to make a compass needle point north. This field averages approximately 500 mG at the earth's surface and is relatively static.
Unlike alternating current (AC) magnetic fields associated with power lines, static or direct current (DC) fields do not cause electrical charges to flow in stationary objects. Thunderstorm activity in the atmosphere is a source of naturally-occurring EMF.
2 Alternating current (AC) magnetic fields
Unlike alternating current (AC) magnetic fields associated with power lines, static or direct current (DC) fields do not cause electrical charges to flow in stationary objects. Thunderstorm activity in the atmosphere is a source of naturally-occurring EMF.