ABSTRACT In this work: - the electric charge definition is formulated; - the refined formula of the electric charge non-invariance is given; - the concept of "the charged particle spin" is clarified; - the electric charge momentum conservation law is obtained; - the angular momentum conservation law for electric charge is obtained; - the formula for the kinetic energy of the translational motion of an electric charge is constructed; - Steiner's theorem for electrodynamics is formulated; - the rotational motion dynamics equation is constructed for electric charge; - the formula for the kinetic energy of the rotational motion of an electric charge is constructed; - a Planck's formula analog for the magnetic field was obtained; - another kind of uncertainty relation was obtained; - formula for the interval between two events is constructed in the electric charge space; - a Reynolds number analog for electromagnetism is obtained; - the experiments results on finding the Reynolds number in electrodynamics are given. Key words: the electric charge non-invariance, the angular momentum of electric charge, the kinetic energy of the rotational motion of an electric charge, a Planck's formula for the magnetic field, a Reynolds number in electrodynamics.

ABSTRACT In this work: - the electric charge definition is formulated; - the refined formula of the electric charge non-invariance is given; - the concept of "the charged particle spin" is clarified; - the electric charge momentum conservation law is obtained; - the angular momentum conservation law for electric charge is obtained; - the formula for the kinetic energy of the translational motion of an electric charge is constructed; - Steiner's theorem for electrodynamics is formulated; - the rotational motion dynamics equation is constructed for electric charge; - the formula for the kinetic energy of the rotational motion of an electric charge is constructed; - a Planck's formula analog for the magnetic field was obtained; - another kind of uncertainty relation was obtained; - formula for the interval between two events is constructed in the electric charge space; - a Reynolds number analog for electromagnetism is obtained; - the experiments results on finding the Reynolds number in electrodynamics are given. Key words: the electric charge non-invariance, the angular momentum of electric charge, the kinetic energy of the rotational motion of an electric charge, a Planck's formula for the magnetic field, a Reynolds number in electrodynamics.