Magnetic Field (H-Field)
Electromagnetic waves are made up of Electric Fields
(often called the E-field) and Magnetic fields (also known as H-fields).
What is an H-field?|
The H-field is a vector quantity (has a magnitude and direction) and is measured in Amps/Meter [A/m]. Recall that the E-field points away from a positive point charge. An H-field curls (or wraps) around a wire of moving charge, as shown in Figure 1. Hence, H-fields are associated with moving electric charges.
Figure 1. H-field associated with a static current.
There are no isolated magnetic charges as of 2008, so an H-field can't be defined as a force per unit magnetic charge in the way an E-field can be defined. However, magnetic dipoles do exist (magnets) which have a positive and negative end (or North and South). The magnetic field lines travel away from the North side and terminate on the south side.
Figure 2. H-field lines associated with magnetic dipole.
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