An electric current branch of resistive unit charge to unit mass core is properly described as a resistor. If this resistive core is reduced to a dimensionless point the mass approaches zero while the charge unity remain the same. This suggests that electric charge is quantized but mass is not. At increasing relativistic speed the mass of an electron approaches infinity as demonstrated by frequent accelerator experiments. However, the electric charge of the electron is a well known relativistic invariance. It is independence of speed: subluminal, luminal, or superluminal.

Since mass is directly equivalent to energy (E=mc), for a conservative unit mass to approach zero physical dimension of length, width, and height, its intrinsic energy must also approaches zero. However, high energy experiments contradict this given logical assertion. It is shown that relativistic length contraction of an electron simultaneously occurs together with its time dilation and increasing its mass and energy. This suggests that a point electron has infinite intrinsic energy. On the other hand if intrinsic energy is directly equivalent to electric charge then both theory and experiment agree. Therefore, intrinsic energy is related to electric charge while extrinsic energy is related to mass. The former is equivalent to potential energy and the latter is equivalent to kinetic energy of classical mechanics.