The following table provides the set of values of V and I obtained for a given diode. Let the characteristics `alpha` be nearly linear, over this range, the forward and reverse bias resistance of the given diode respectively are

Options

A. `10 Omega , 8 xx 10^6 Omega`
B. `20 Omega , 4 xx 10^5 Omega`
C. `20 Omega , 8 xx 10^6 Omega`
D. `10 Omega , 10 Omega`

Answer

C

Explanation

For forward biasing, `DeltaV`=2.4-2.0=0.4 V
`DeltaI`=80-60 = 20 mA
`therefore r_(fb)=(DeltaV)/(DeltaI)=0.4/(20xx10^(-3))=20 Omega`
For reverse biasing, `DeltaV`= -2-0=-2V
`DeltaI` = -0.25-0= `-0.25 muA`
`r_(rb)=(-2)/(-0.25xx10^(-6))=8xx10^6 Omega`