  The study of the polarization direction is crucial in the issue of restoring
the spatial structure of the magnetic field in the active galaxy parsec-scale
jets. But, due to relativistic effects, the magnetic field projected onto the
celestial sphere in the source reference frame cannot be assumed to be
orthogonal to the observed direction of the electric vector in the wave.
Moreover, the local axis of the jet component may not coincide with its motion
direction, which affects the observed polarization direction. In this article,
we analyze the transverse to jet distributions of the electric vector in the
wave, obtained as a result of modeling with different jet kinematic and
geometrical parameters for a helical magnetic field with a different twist
angle and for a toroidal magnetic field in the center, surrounded by a varying
thickness sheath, penetrated by a poloidal field. We obtained: 1) the shape of
the electric vector transverse distribution depends in a complex way on the
angles of the jet axis and the velocity vector with the line of sight; 2)
ambiguity in determining the twist direction of the helical magnetic field
under using only the distributions of the electric vector in the wave; 3) both
considered magnetic field topologies can reproduce both the ``spine-sheath''
polarization structure and individual bright details with the longitudinal to
the jet axis polarization direction.
