For common emitter configuration, if `alpha and beta` have their usual meanings, the incorrect relationship between `alpha and beta` is :

Options

A. `(1)/(alpha)=(1)/(beta)+1`
B. `alpha=(beta)/(1-beta)`
C. `alpha=(beta)/(1+beta)`
D. `alpha=(beta^(2))/(1+beta^(2))`

Answer

B

Explanation

`(B) alpha=(beta)/(1-beta) (D) alpha=(beta^(2))/(1+beta^(2))`
For transistor `I_(E )=I_(B)+I_(C )`
`therefore (I_(B))/(I_(C ))=(I_(B))/(I_(C ))+1`
`therefore (1)/(alpha)=(1)/(beta)+1" "`(Option (A) is correct)
`therefore (1)/(alpha)=(1+beta)/(beta)`
`therefore alpha=(beta)/(1+beta)" "` (Option C is correct)
`therefore` Option (B) and (D) are not correct.