To the Question of a “Magnetic Field Work”

The known problem of a “magnetic field work” is discussed. This work is usually declared null due to the zero product of the complanar vectors scalar triple product – the Lorentz force and the power expression contain the same speed vector. The application of the refined work determination including the differential of a path as Maclaurin series with the 2nd term accuracy leads to the nonzero work value. The conditions of this work accounting are determined as well as the physical consequences of this accounting for any forces normal to speed. Besides, the problems of a magnetic field and an immobile probe charge interaction as well as the 3rd Newton law fulfillment are discussed.