1. R S Bridge rectifier circuit: The voltage drop upon the resistor is positive no matter the voltage of the voltage source. Potential graph representation: Potential difference of edge R is positive no matter the potential difference in the source S. Graph Properties Reflected as Physical Properties of Engineering Systems

2. R S The graph is self-dual, therefore flows manifest the same property: the flow through edge R is positive no matter the flow in the flow source S R S This property in the terminology of the electronic circuit reads: the current through the resistor is positive no matter the current of the current source Graph Properties Reflected as Physical Properties of Engineering Systems

3. The corresponding graph is not self-dual Another voltage rectifying circuit 4 Cannot serve also as a current rectifier Graph Properties Reflected as Physical Properties of Engineering Systems