Remanence is the effect of the magnetic flux left behind after an electromagnetic field is removed from a medium. This effect usually occurs when it is exposed to a powerful external magnetic field and the external field is removed. After magnetic induction, it is the remaining energy in the magnetic medium after the removal of applied magnetizing force. Generally it connotes residual information left on electromagnetic storage media after reformating or cleaning.
The property of the magnetic conducting medium determines the ability to retain a magnetic quantity whose modulation represents information. Remanence is measure of the magnetic flux density while no magnetic field is applied. Remanence is less than the residual induction in magnets, ferromagnetic conductive mediums, and electromagnetic circuits.
It is denoted in equations by Bd or Mr.
Remanence has application in geology (concerning paleomagnetism), computer engineering (concerning data storage and recovery), and physics (concerning electromagnetics).
