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:
“In the west, Apollo and Dionysus strive for victory. Apollo makes the boundary lines that are civilization but that lead to convention, constraint, oppression. Dionysus is energy unbound, mad, callous, destructive, wasteful. Apollo is law, history, tradition, the dignity and safety of custom and form. Dionysus is the new, exhilarating but rude, sweeping all away to begin again. Apollo is a tyrant, Dionysus is a vandal.”
—Camille Paglia (b. 1947)
“Suddenly I’m not half the girl
I used to be.
There’s a shadow hanging over me . . .
From me to you out of my electric devil....”
—Anne Sexton (1928–1974)
“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)
“The sun was like a great visiting presence that stimulated and took its due from all animal energy. When it flung wide its cloak and stepped down over the edge of the fields at evening, it left behind it a spent and exhausted world.”
—Willa Cather (1873–1947)