Question

4. Consider the following statements S, and S.
S: The B of a bipolar transistor reduces if the base
width is increased.
S2: The B of a bipolar transistor increases if the
doping concentration in the base is increased.
Which one of the following is correct?
(a) S, is FALSE and S, is TRUE
(b) Both S, and S, are TRUE
(c) Both S, and S, are FALSE
(d) S, is TRUE and S, is FALSE
a
b
c
d​

Answer 1

Answer:

Correct option (d) S1 TRUE and S2 is FALSE

Explanation :

Note the relation between α andβ current gains

β=ic /ib=α /1--α

If base width of transistor increases, recombination in base region increases, and thus α decreases and hence β decreases.

Thus S1 is true

If doping of base region increases, then recombination is base increases and α decreases thereby decreasing β

thus S2 is true false