Question 4.16: Determine the forward resistance of a PN junction diode when...

Given For a silicon diode, the forward current, I = 5 mA, T = 300 K

Forward resistance of a PN junction diode, r_{f}=\frac{\eta V_{T} }{I}, where V_{T}=\frac{T}{11,600} and η = 2 for silicon

Therefore,                            r_{f}=\frac{2\times \frac{T}{11,600}}{5\times 10^{-3} }=\frac{2\times 300}{11,600\times 5\times 10^{-3} }=10.34  \Omega