Junction Transistor
For transistor action
(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. Which one of the following pairs of statements is correct?
Show answer and solution
Answer: (c)
- (1) is wrong: regions have different sizes and doping.
- (2) is right: base is very thin and lightly doped.
- (3) is right: E-B junction forward biased, B-C junction reverse biased.
- (4) is wrong: if both are forward biased the transistor is in saturation, not active.
- So the answer is (c) (2) and (3).