Search results
Results from the WOW.Com Content Network
The magnetic field (marked B, indicated by red field lines) around wire carrying an electric current (marked I) Compass and wire apparatus showing Ørsted's experiment (video [1]) In electromagnetism , Ørsted's law , also spelled Oersted's law , is the physical law stating that an electric current induces a magnetic field .
The Induced current is the current generated in a wire due to change in magnetic flux. An example of the induced current is the current produced in the generator which involves rapidly rotating a coil of wire in a magnetic field. It is a qualitative law that specifies the direction of induced current, but states nothing about its magnitude.
The Hall effect is the production of a potential difference (the Hall voltage) across an electrical conductor that is transverse to an electric current in the conductor and to an applied magnetic field perpendicular to the current.
The original form of Maxwell's circuital law, which he derived as early as 1855 in his paper "On Faraday's Lines of Force" [9] based on an analogy to hydrodynamics, relates magnetic fields to electric currents that produce them. It determines the magnetic field associated with a given current, or the current associated with a given magnetic field.
Magnetic field (green) induced by a current-carrying wire winding (red) in a magnetic circuit consisting of an iron core C forming a closed loop with two air gaps G in it. In an analogy to an electric circuit, the winding acts analogously to an electric battery, providing the magnetizing field , the core pieces act like wires, and the gaps G act like resistors.
When the electric current in a loop of wire changes, the changing current creates a changing magnetic field. A second wire in reach of this magnetic field will experience this change in magnetic field as a change in its coupled magnetic flux, . Therefore, an electromotive force is set up in the second loop called the induced emf or transformer emf.
Many times in the use and calculation of electric and magnetic fields, the approach used first computes an associated potential: the electric potential, , for the electric field, and the magnetic vector potential, A, for the magnetic field. The electric potential is a scalar field, while the magnetic potential is a vector field.
In many useful cases, a distribution of electric charge can be mathematically replaced by an equivalent distribution of magnetic current. This artifice can be used to simplify some electromagnetic field problems. [b] [c] It is possible to use both electric current densities and magnetic current densities in the same analysis. [4]: 138