  We address recent experiments shedding light on the energy spectrum of under-
and optimally doped cuprates at temperatures above superconducting transition.
Angle resolved photoemission reveals coherent excitation only near nodal points
on parts of the "bare" Fermi surface known as the Fermi arcs. The question
debated in the literature is whether the small normal pocket, seen via quantum
oscillations exists at higher temperatures or forms below a charge order
transition in strong magnetic fields. Assuming the former case as possibility,
expressions derived for the resistivity and the Hall coefficient (in weak and
strong magnetic fields) with both types of carriers participating in transport.
There are two regimes. At higher temperatures (at a fixed field) electrons are
dragged by the Fermi arcs' holes. The pocket being small its contribution into
conductivity and the Hall coefficient is negligible. At lower temperatures
electrons decouple from holes behaving as a Fermi gas in the magnetic field.
Mobility of holes on the arcs decreasing in strong fields with decrease of
temperature, below a crossover point the pocket electrons prevail changing sign
of the Hall coefficient in the low temperature limit. Such behavior finds its
confirmation in recent high-field experiments.
