Thank for the reply. I understand the when apply positive terminal power to the base in a NPN transistor, the depletion region between NP get decrease (while ground emiter). as a result, it NP junction operate at forward biasing (The turn on voltage is 0.7 volt). However, if i also apply positive terminal power to the other N region (the collector, the other half of the NPN), the depletion between the PN junction is increasing. As a result, there should be no current flow between the PN. I look at my lecture note, it claim that most current is flow through there. I am still confuse. can you guy explain.
Thank you.