  The electromagnetically induced transparency (EIT) phenomenon has been
investigated in a $\Lambda$-system of the $^{87}$Rb D$_1$ line in an external
transverse magnetic field. Two spectroscopic cells having strongly different
values of the relaxation rates $\gamma_{rel}$ are used: a Rb cell with
antirelaxation coating ($L\sim$1 cm) and a Rb nanometric-thin cell (nano-cell)
with thickness of the atomic vapor column $L$=795nm. For the EIT in the
nano-cell, we have the usual EIT resonances characterized by a reduction in the
absorption (i.e. dark resonance (DR)), whereas for the EIT in the Rb cell with
an antirelaxation coating, the resonances demonstrate an increase in the
absorption (i.e. bright resonances). We suppose that such unusual behavior of
the EIT resonances (i.e. the reversal of the sign from DR to BR) is caused by
the influence of alignment process. The influence of alignment strongly depends
on the configuration of the coupling and probe frequencies as well as on the
configuration of the magnetic field.
