  The Temporal and Spectral variations of black hole candidates during
outbursts have been reported in several publications. It is well known that
during an outburst, the source becomes soft in the first few days, and then
returns to the hard state after a few weeks or months. In the present paper, we
show the variation of Comptonization Efficiency (CE), obtained from the ratio
of the black body photon number to the power-law photon number, as a function
of time in several outbursts. Since the power-law photons are generated through
inverse-Comptonization of the intercepted soft photons, the CE is a measure of
the geometry of the Compton cloud. Our investigation indicated that all the
outbursts starts with a large CE and becomes very small after a few days, when
the Compton cloud becomes very small to intercept any significant number of
soft photons. CE returns back to a larger value at the end of the outburst.
