Energy Density of Electric and Magnetic Fields
Electric and magnetic fields store energy. In a vacuum, the (volumetric) energy density (in SI units) is given by
where E is the electric field and B is the magnetic field. The solution will be in Joules per cubic metre. In the context of magnetohydrodynamics, the physics of conductive fluids, the magnetic energy density behaves like an additional pressure that adds to the gas pressure of a plasma.
In normal (linear) substances, the energy density (in SI units) is
where D is the electric displacement field and H is the magnetizing field.
Read more about this topic: Energy Density
Famous quotes containing the words energy, electric, magnetic and/or fields:
“Parents find many different ways to work their way through the assertiveness of their two-year-olds, but seeing that assertiveness as positive energy being directed toward growth as a competent individual may open up some new possibilities.”
—Fred Rogers (20th century)
“The more I see of democracy the more I dislike it. It just brings everything down to the mere vulgar level of wages and prices, electric light and water closets, and nothing else.”
—D.H. (David Herbert)
“We are in great haste to construct a magnetic telegraph from Maine to Texas; but Maine and Texas, it may be, have nothing important to communicate.”
—Henry David Thoreau (1817–1862)
“But famished field and blackened tree
Bear flowers in Eden never known.
Blossoms of grief and charity
Bloom in these darkened fields alone.”
—Edwin Muir (1887–1959)