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# KCC's Quizzes AQQ254 about Thevenin & Norton Dipôles enigma

And here is a new quiz!

Many existing courses, articles, etc represent the Thevenin-Norton equivalent dipoles as shown above.

However, there is something wrong somewhere. For example, the Thevenin dipole as represented does not consume any energy while the Norton equivalent does! Theory said they must be pretty equivalent.

Question: What's wrong and how will you rectify the schematics?

Updated text.
[edited by: emassa at 2:08 PM (GMT -5) on 27 Feb 2024]
• What's missing is the load resistance!

• 1) I believe it's only an equivalent transformation specifically with respect to a load or in a circuit that is intended to be loaded. Redefinition, not really a rebuttal. Currently at Node A-B, you can only see the same voltage.

2) Adding a load to node A-B will make both circuits effectively equivalent assuming that the Thevenin/Norton were derived from the same circuit and choosing the same load to remove for analysis. In this case, both circuits will yield the same power/energy consumption/whatnots.

• Is there something wrong? For example, the open circuit Thevenin dipole as represented does not consume any energy while the open circuit Norton equivalent does but the short circuit Thevenin dipole as represented does consume energy while the short circuit Norton equivalent does not. Theory says they are equivalent with respect to an external load.

• The equivalents behave similarly for  a given resistive load. The equivalent itself is not "equivalent" but produces equivalent current and voltage for a resistive load.

One limitation of these models is that they are limited to resistive loads. One way to improve the models is to change the source to a real frequency variable source and to change the resistors to an RLC network that produces equivalent impedance over the frequency range of the load.