space permeability [`spās ´pǝr·mē·ǝ`bil·ǝd·ē] ELECTROMAGNETISM Factor that expresses the ratio of magnetic induction to magnetizing force in a vacuum; in the centimeter-gram-second electromagnetic system of units, the permeability of a vacuum is arbitrarily taken as unity; in the meter-kilogram-second-ampere system, it is 4π × 10-7. |