Hi! The VCEsat which occurs between the emitter and the collector of a saturated bjt is duo to the inevitable loss of energy caused by the resistance between the emitter and the collector, right? If so, why this voltage drop is bigger at higher currents and lower at smaller ones? For example at Ib to Ic ratio of 1 to 10, at Ic=250mA Vcesat=,2V. But at the same base to collector current ratio, at Ic=500mA Vcesat=1V. Also I always wanted to ask someone, as an engineer, how deep do you need to go with physical explanations?