  The paradox of a field of a moving locked charge (confined in a closed space)
is considered and solved with the use of the integral Maxwell equations. While
known formulas obtained for instantaneous fields of charges moving along
straight and curved lines are fully correct, measurable quantities are average
electric and magnetic fields of locked charges. It is shown that the average
electric field of locked charges does not depend on their motion. The average
electric field of protons moving in nuclei coincides with that of protons being
at rest and having the same spatial distribution of the charge density. The
electric field of a twisted electron is equivalent to the field of a centroid
with immobile charges which spatial distribution is defined by the wave
function of the twisted electron.
