In classical electromagnetism, the<unk>  (or electric<unk> , or simply<unk>  is the vector field that expresses the<unk>  of  permanent or induced electric dipole moments in a dielectric material. The<unk>  vector P is defined as the dipole moment per unit volume.  The SI unit of measure is coulombs per square metre.
Polarization density
QRS complex
Resting potential
Extraction ratio
RR interval
Ventricular action potential
E/a ratio
Angular resolution