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What is the Lorentz Force Law and how does it relate to DC Electric Motors?

CATEGORY : DC Electric Motor

Posted by John on 17 Feb, 2012

The Lorentz Force Law describes the effects of a charged particle moving through a constant magnetic field. The scalar equation provides the simplest example of this law, where F=QvB and F is the force acting on the particle, v is the velocity of the particle, Q is the charge of the particle and B is the magnetic field.

The charged particle in the magnetic field contained in a live DC circuit can be electrons, ions or plasma. Plasma is any matter that has been heated to the point where it is electrically conductive, and can be commonly seen as electrical sparks. In a DC electric motor, the charged electrons move at a relatively high speed around a guiding centre, according to the Lorentz force law. This movement of charged particles is what determines the movement of a live current in DC electric motors.

The Lorentz Law continues to be a significant guiding principle in the design and engineering of all types of engines. The law states that a live current running through a wire in a magnetic field causes a force to develop with the direction and magnitude described by the 'right hand rule,' where the magnetic force is always perpendicular to both the magnetic field and charge velocity.

The Lorentz Force causes conductors in basic circuits to accelerate away from the current source, thus producing mechanical motion, from a live current in the motor. The Lorentz Force also typifies how a circuit produces voltage from velocity, to work as a power generator.