Active Region or Linear Region

Active Region or Linear Region:

Sometimes called the linear region. It refers to that part of the collector curve that is approximately horizontal. A transistor operates in the active region when it is used as an amplifier. In the active region, the emitter diode is forward-biased, the collector diode is reverse-biased, the collector current almost equals the emitter current, and the base current is much smaller than either the emitter or collector current.