Which one of the following theorems is a manifestation of the Law of Conservation of Energy?

Different theorems used in the electrical network:

1.) Tellegen's Theorem

• It states that the power consumed by all the passive elements is always equal to the power delivered by all active elements.
• Hence, this theorem is a manifestation of the Law of Conservation of Energy.

2.) Reciprocity Theorem:

• It states that if the source and response of an electrical network are interchanged, then the parameters of the circuit remain the same.

3.) Thevenin's Theorem:

• It states that any linear circuit containing several sources and resistances can be replaced by just one single voltagesource in series with a single resistance connected across the load.

4.) Norton's Theorem:

• It states that any linear circuit containing several sources and resistances can be replaced by just one single current source in paralledwith a single resistance connected across the load.