Right-hand screw rule

From Citizendium
Revision as of 02:38, 18 July 2008 by imported>Paul Wormer
Jump to navigation Jump to search
This article is developing and not approved.
Main Article
Discussion
Related Articles  [?]
Bibliography  [?]
External Links  [?]
Citable Version  [?]
 
This editable Main Article is under development and subject to a disclaimer.
Corkscrew driven by right hand downward into the cork.

The right-hand screw rule, also known as corkscrew rule, associates the direction of an electric current with the direction of the magnetic force lines circling the current, see Ampère's law.

By convention, an electric current runs from positive to negative voltage (in a direction opposite the actual flow of the—negatively charged—electrons). The magnetic field points toward the North pole, i.e., a compass needle will align itself along (be tangent to) the green magnetic field line in the figure, pointing in the same direction as the green arrow.

The corkscrew rule is depicted in the figure, where the corkscrew is rotated downward into the cork. When the electric current runs straight downward through the center of the corkscrew, the magnetic force lines are directed along the green line shown in the photograph.