Question

For transistor action, state which statements are true:
(1) Base, emitter and collector regions should have similar size and doping concentrations.
(2) The base region must be very thin and lightly doped.
(3) The emitter-base junction is forward biased and base-collector junction is reverse biased
(4) Both the emitter-base junction as well as the base-collector junction are forward biased

• A. (4) and (1)
• B. (1) and (2)
• C. (2) and (3)
• D. (3) and (4)

Answer 1

Answer: (C)

(2) and (3)

The key to the fabrication of a transistor is to make the middle layer, the base, as thin as possible without shorting the outside layers.
It is customary to forward bias the emitter-base junction of a bipolar junction transistor as this increases the width of the depletion region whereas base collector junction is reverse biased.