Semiconductor Electronics Materials Devices And Simple Circuits Ques 68
68. For transistor action, which of the following statements is correct?
[2020]
(a) Base, emitter and collector regions should have same size.
(b) Both emitter junction as well as the collector junction are forward biased.
(c) The base region must be very thin and lightly doped.
(d) Base, emitter and collector regions should have same doping concentrations.
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Answer:
Correct Answer: 68.(c)
Solution:
- (c) In a transistor, emitter is heavily doped, the base region is lightly doped and thin. The size of collector region is larger than other two regions.
Length profile in transistor is $L_C>L_E>L_B$ and doping profile in transistor is $E>C>B$. For transistor action Base-emitter junction is forward biased and Base-collector junction is reversed biased.
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