A charge of 8.0 mA in the emitter current brings a charge of 7.9 mA in the collector current. The values of `alpha and beta` are

Options

A. `0.99, 90`
B. `0.96,79`
C. `0.97,99`
D. `0.99,79`

Answer

D

Explanation

Given that, change in emitter current, `DeltaI_(E)=8mA`
and change in collector current, `DeltaI_(C)=7.9mA` We know that,
`alpha=(DeltaI_(C))/(DeltaI_(E))impliesalpha=(7.9)/(8)impliesalpha~-0.99`
Also we know that
`beta=(alpha)/(1-alpha)`
`impliesbeta=((7.9)/(8))/(1-(7.9)/(8))=(7.9)/(8-7.9)`
or `beta=(7.9)/(0.1)=79`
Hence, the required answer is `alpha=0.99andbeta=79`