Direct Current Electrical Motor

This Java applet shows a direct current electrical motor which is reduced to the most important parts for clarity. Instead of an armature with many windings and iron core, there is only a single rectangular conductor loop; the axis the loop rotates on is omitted.

The blue arrows indicate the conventional current direction (from + to -). You can recognize the magnetic field lines (directed from the red painted north pole to the green painted south pole) by the red color. The black arrows represent the Lorentz force which is exerted to a current-carrying conductor in the magnetic field.

The mentioned Lorentz force is orthogonal to the direction of current and to the magnetic field lines. The orientation of this force results from the well-known third hand rule


current direction

Fingers (uncurled):

Magnetic field

Palm facing:

Lorentz force

You need a Java enabled browser to view this applet.

Walter Fendt, November 29, 1997
Last modification: January 15, 1999

Slight modifications to the wording were made by Steve Wirt.

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