In a transistor , the value of `alpha` veries between `(20)/(21) and (100)/(101)` . Then the value of `beta` varies between

Options

A. 1 and 10
B. 0.95 and 0.99
C. 20 and 100
D. 200 and 300

Answer

C

Explanation

Given, in a transistor current gain,
`alpha = (20)/(21) and (100)/(101)`
Now, common emitter transistor
DC current gain, `beta = (alpha)/(1 -alpha)`
case I if `alpha = (20)/(21) , then beta = ((20)/(21))/(1 - (20)/(21) ) = 20 `
case II `alpha = (100)/(101), "then" beta = ((100)/(101))/(1 - (100)/(101)) = 100 `
`therefore` Value of beta varies between , beta in [ 20, 100]. `