Question

In a transistor, collector current is controlled by the _________. In a PNP transistor, the main flow of current is controlled by altering the number of _________. In an NPN transistor, the main flow of current is controlled by altering the number of _________.

Answer 1

The collector current in a transistor is controlled by the base current, with the main flow in a PNP transistor controlled by holes and in an NPN transistor by free electrons.

Step-by-step explanation:

In a transistor, the collector current is controlled by the base current. Specifically, in a PNP transistor, the main flow of current is controlled by altering the number of holes. Conversely, in an NPN transistor, the main flow of current is controlled by altering the number of free electrons. The base current acts as a valve that allows the control of the collector current in both PNP and NPN transistors, and by doping the semiconductor material with impurities, it is possible to control the majority carriers in the device, which are holes in PNP transistors and free electrons in NPN transistors.