Skip to main content
Engineering LibreTexts

3.6: Questions

  • Page ID
  • \( \newcommand{\vecs}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}} } \) \( \newcommand{\vecd}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash {#1}}} \)\(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\) \(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\)

    1. Is 0.7 volts a reasonable approximation for a forward bias potential? Is an open circuit a reasonable approximation for a reverse biased diode? Support your arguments with experimental data.

    2. The “average” resistance of a forward biased diode can be computed by simply dividing the diode's voltage by its current. Using Table 3.5.1, determine the smallest average diode resistance (show work).

    3. The instantaneous resistance (also known as AC resistance) of a diode may be approximated by taking the differences between adjacent current-voltage readings. That is, \(r_{diode} = \Delta V_{diode}/\Delta I_{diode}\). What are the smallest and largest resistances using Table 3.5.1 (show work)? Based on this, what would a plot of instantaneous diode resistance versus diode current look like?

    4. If the circuit of Figure 3.3.3 had been constructed with LEDs in place of switching diodes, would there be any changes to the values measured in Table 3.5.3? Why/why not?

    3.6: Questions is shared under a CC BY-NC-SA 4.0 license and was authored, remixed, and/or curated by James M. Fiore via source content that was edited to conform to the style and standards of the LibreTexts platform; a detailed edit history is available upon request.