Hello. Let me think about the NPN transistor (Collector-Base-Emitter order). Here base-emitter voltage is forward-biased (The base is higher than the emitter in voltage.) thus current flow of majority carriers (Here they are electrons in N and holes in P) occurs from emitter to base. In next, the collector and base is now reverse-biased. (Collector is higher than base in voltage.) This reverse bias basically prevents majority carrier flow in NP junction but allows only minority carrier flow. But here in base there is presence of large number of electrons which actually came from the emitter by forward-bias between PN junction and electron in base (P-type extrinsic semiconductor) is minority! Thus they can flow to collector. In conclusion, current flow from emitter and collector ICE is made. Here is my question: in this logic, where is base current? what is the source of base current? I've suspected it is minority current in reverse-biased collector-base but they can be going to emitter since they see forward-bias between base to emitter! Could you please clarity this?