  We study the time variability and spectral evolution of the Black Hole
Candidate source XTE J1650-500 using the BeppoSax wide energy range (0.12-200
keV) observations performed during the 2001 X-ray outburst. The source evolves
from a low/hard state (LHS) toward a high/soft state (HSS). In all states the
emergent photon spectrum is described by the sum of Comptonization and soft
(disk) blackbody components. In the LHS, the Comptonization component dominates
in the resulting spectrum. On the other hand, during the HSS the soft (disk)
component is already dominant. In this state the Comptonization part of the
spectrum is much softer than that in the LHS (photon index is ~ 2.4 in the HSS
vs. that is ~1.7 in the LHS). In the BeppoSAX data we find a strong signature
of the index saturation with the mass accretion rate which can be considered as
an observational evidence of the converging flow (black hole) in XTE J1650-500.
We derive power spectra (PS) of the source time variability in different
spectral states as a function of energy band. When the source undergoes a
transition to softer states, the PS as a whole is shifted to higher frequencies
which can be interpreted as a contraction of the Compton cloud during hard-soft
spectral evolution. It is worthwhile to emphasize a detection of a strong
low-frequency red noise component in the HSS PS which can be considered a
signature of the presence of the strong extended disk in the HSS. Also as a
result of our data analysis, we find a very weak sign of K_alpha line
appearance in these BeppoSAX data. This finding does not confirm previous
claims by Miniutti et al. on the presence of a broad and strongly relativistic
iron emission line in this particular set of the BeppoSAX data.
