Q. For transistor action (a) Base, emitter and collector regions should have similar size and doping concentrations. (b) The base region must be very thin and lightly doped. (c) The emitter-base junction is forward biased and base-collector junction is reverse biased. (d) Both the emitter-base junction as well as the base collector junction are forward biased. Which one of the following pairs of statements is correct?
A) (d), (a)
B) (a), (b)
C) (b), (c)
D) (c), (d)
Explanation
[Solution from source] A transistor works because the base is very thin and lightly doped, and in active mode the emitter-base junction is forward biased while the collector-base junction is reverse biased. The regions are deliberately unequal in size and doping, and forward-biasing both junctions puts the transistor in saturation, not normal transistor action. Answer (3).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.