
concepts
Get flash to fully experience Pearltrees
Permeability (electromagnetism)
In electromagnetism , permeability is the measure of the ability of a material to support the formation of a magnetic field within itself.Magnetic monopole
It is impossible to make magnetic monopoles from a bar magnet . If a bar magnet is cut in half, it is not the case that one half has the north pole and the other half has the south pole.Magnetic flux
Magnetic field of an ideal cylindrical magnet with its axis of symmetry inside the image plane.
Magnetic field
Gaussian surface
A cylindrical Gaussian surface is commonly used to calculate the electric charge of an infinitely long, straight, 'ideal' wire. A Gaussian surface is a closed surface in three dimensional space through which the flux of a vector field is calculated; usually the gravitational field , the electric field, or magnetic field. [ 1 ] It is an arbitrary closed surface S = ∂V V used in conjunction with Gauss's law for the corresponding field ( Gauss' law for gravity , Gauss' law for electricity , or Gauss' law for magnetism ) by performing a surface integral , in order to calculate the total amount of the source quantity enclosed, i.e. amount of gravitational mass as the source of the gravitational field or amount of electric charge as the source of the electrostatic field, or vice versa: calculate the fields for the source distribution. For concreteness, the electric field is considered in this article, as this is the most frequent type of field the surface concept is used for.Electromagnetic radiation
Electromagnetic induction is the production of a potential difference (voltage) across a conductor when it is exposed to a varying magnetic field .
Electromagnetic induction
An electromagnetic field (also EMF or EM field ) is a physical field produced by electrically charged objects . It affects the behavior of charged objects in the vicinity of the field. The electromagnetic field extends indefinitely throughout space and describes the electromagnetic interaction .
Electromagnetic field
Electrical resistance
Permittivity
Electric field lines emanating from a point positive electric charge suspended over a negatively charged infinite sheet An electric field surrounds electrically charged particles and time-varying magnetic fields .
Electric field
Electrical conductivity
Electrical resistivity (also known as resistivity , specific electrical resistance , or volume resistivity ) quantifies how strongly a given material opposes the flow of electric current . A low resistivity indicates a material that readily allows the movement of electric charge . Resistivity is commonly represented by the Greek letter ρ ( rho ).A simple electric circuit, where current is represented by the letter i . The relationship between the voltage (V), resistance (R), and current (I) is V=IR; this is known as Ohm's Law .

