Force On A Current-carrying Wire
When a wire carrying an electrical current is placed in a magnetic field, each of the moving charges, which comprise the current, experiences the Lorentz force, and together they can create a macroscopic force on the wire (sometimes called the Laplace force). By combining the Lorentz force law above with the definition of electrical current, the following equation results, in the case of a straight, stationary wire:
where ℓ is a vector whose magnitude is the length of wire, and whose direction is along the wire, aligned with the direction of conventional current flow I.
If the wire is not straight but curved, the force on it can be computed by applying this formula to each infinitesimal segment of wire dℓ, then adding up all these forces by integration. Formally, the net force on a stationary, rigid wire carrying a steady current I is
This is the net force. In addition, there will usually be torque, plus other effects if the wire is not perfectly rigid.
One application of this is Ampère's force law, which describes how two current-carrying wires can attract or repel each other, since each experiences a Lorentz force from the other's magnetic field. For more information, see the article: Ampère's force law.
Read more about this topic: Lorentz Force
Famous quotes containing the words force on, force and/or wire:
“We are to have a tiny party here tonight; I hate tiny
parties—they force one into constant exertion.”
—Jane Austen (1775–1817)
“The conduct of God who disposes all things kindly, is to put religion into the mind by reason, and into the heart by grace. But to attempt to put it into the mind and heart by force and threats is not to put religion there, but terror.”
—Blaise Pascal (1623–1662)
“A new idea is rarely born like Venus attended by graces
More commonly it’s modeled of baling wire and acne.
More commonly it wheezes and tips over.”
—Marge Piercy (b. 1936)