Question

Silicon semiconductor p-n junction diode has a barrier potential of 0.78 volt calculate the series resistance which should be connected to the PN junction so that it allows 1 milliampere current to flow in the circuit with a 5 volt battery used to provide forward bias to it?

Answer 1

$$\begin{gathered} forwardbiasedvoltagedropacrossthediodeis0.78volt. \\ thecurrentthroughthediodeis \\ I=\frac{V-0.78}{R} \\ {10}^{-3}=\frac{5-0.78}{R} \\ R=4.22*{10}^3=4.22kiloohm \\ Regards \end{gathered}$$