Question

The active region operation of a transistor is:
A. The collector-emitter junction is forward biased.
B. The collector-emitter junction is reverse biased.
C. The collector-base junction is forward biased and the emitter junction is reverse biased.
D. The collector junction is reverse biased and the emitter base junction is forward biased.

Answer 1

Hint:In which transistors have many applications is called active region. It is also called a linear region. In this region the transistor acts well as an amplifier. Now we are going to discuss the active region and give options in detail step by step in the complete step by step solution.

Complete step by step answer:
Active region lies between saturation and cutoff. The transistor in this operates in an active region, when the collector junction is reverse biased and emitter junction is forward biased.The transistor will function normally.
Cut-Off: In the cut-off region, the emitter diode and collector diode are off.
Saturation: Emitter diode and collector diode are on.

Active: In the active region, the emitter diode is on and the collector diode is off.Collector base junction is reverse biased, whereas base emitter junction is forward biased.The transistor is said to operate in the active region. In the p-n-p transistor the operation is in the active region, whereas in the n-p-n transistor the operation is in the active region. Emitter base injects a large amount of charge carrier to the base. Section which collects the majority of charge carriers and supplied by the emitter is called collector. Emitter size is more than base but less than the collector.

Note:Biasing to the transistor ensures that it operates in the active region. In the active region, the emitter-base is forward biased and the collector-base is reverse biased.Unlike the resistors, which have a linear relation between voltage and current, the transistors are nonlinear devices. In order to operate in active mode, the transistor’s voltage in base-emitter junction must be greater than zero while in base-collector mode must be negative. It means that the base voltage must be less than the collector but greater than the emitter.