Normal state of extremely anisotropic superconducting cuprates as revealed by magnetotransport

High magnetic-field studies of cuprate superconductors revealed a non-BCS temperature dependence of the upper critical field Hc2(T) determined resistively by several groups. These determinations caused some doubts on the grounds of both the contrasting effect of the magnetic field on the in-plane and out-of-plane resistances reported for large Bi2212 samples and the large Nernst signal well above Tc. Here we present both ρab(B) and ρc(B) of tiny Bi2212 crystals in magnetic fields up to 50 T. None of our measurements revealed a situation when on the field increase ρc reaches its maximum while ρab remains very small if not zero. The resistive Hc2(T) estimated from ρab(B) and ρc(B) are approximately the same. Our results support any theory of cuprates that describes the state above the resistive phase transition as perfectly normal with a zero off-diagonal order parameter.