Help with node voltage

  • #1
Say you are analyzing a circuit. Will the node voltages depend on where you set your reference node? Because, i did a circuit problem and set the reference node to a different node each time and, i got the same answer overall, but my potential across a certain node was different each time. Am i doing something wrong? Because, i thought that if current comes out a voltage source one way (not towards the reference), then it will be reduced based on the resistors in that branch towards the node. THat way, the node voltage will change based on where you arbitrarily place the reference. is there a rule for this, or do i just not understand how it works?
 

Answers and Replies

  • #2
chroot
Staff Emeritus
Science Advisor
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All voltages (potentials) are relative. People usually declare some node "ground" and give it a fixed voltage of zero, then measure all other voltages relative to it.

You can just as easily assign that node any other value you want. Let's say instead of declaring it to have a voltage of zero volts, you declared it to have a potential of one volt. The potential difference between any two nodes in the circuit will be the same as always, but now every voltage in the circuit will have one added to it.

- Warren
 

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