Answer 1

Three segments of transistor: 

1. Emitter - Segment is on one side of the transistor. It is of moderate size and heavily doped. It supplies a huge number of majority carriers for the current flow through the transistor.
2. Base - It is the central segment. It is very thin and lightly doped.
3. Collector - It collects a major portion of the majority carrier supplied by the emitter. It is moderately doped and large in size compared to the emitter.