I'll let deeper thinkers than myself determine the number of angels that can dance on the head of a pin.

We did that in Chemistry 101.
That does not suggest that I'm a, "deep thinker".
I'm so shallow that I can't understand how it helps the TS to run off into things that call a college degree into question.
Guys. please. Try not to scramble the kid's brains while you tete-a-tete.

 

They are the same thing. You can only measure a voltage (potential difference) across some drvice in which current can flow. This device could be a battery, a resistor, an inductor, a capacitor, or a piece of wire. Ohm's law tells us that when the current through the device is zero, the voltage (potential difference) is also zero. Any non-zero current flow through the device will result in a non-zero voltage (potential difference) across the device.

This is an electronics engineer's point of view. A physicist does not need to invoke the Ohm's law to define a potential difference between two points of space which is just the integral of the electric field through any path between these two points, and the electric field can exist in vacuum where no current can flow.

 

This is an electronics engineer's point of view. A physicist does not need to invoke the Ohm's law to define a potential difference between two points of space which is just the integral of the electric field through any path between these two points, and the electric field can exist in vacuum where no current can flow.

And I forgot to add: the voltage is equal to potential difference only for static fields, for time varying fields they are not the same! Consider a generator where a voltage is induced in a wire loop by varying the magnetic field flux : obviously this induced voltage cannot be obtained by subtracting potentials (then in the integral defining the potential difference we have to add the time derivative of the magnetic vector potential)

 

And I forgot to add: the voltage is equal to potential difference only for static fields, for time varying fields they are not the same! Consider a generator where a voltage is induced in a wire loop by varying the magnetic field flux : obviously this induced voltage cannot be obtained by subtracting potentials (then in the integral defining the potential difference we have to add the time derivative of the magnetic vector potential)

The issue isn't static versus time-varying electric fields. It is conservative versus non-conservative electric fields.

 

This is an electronics engineer's point of view. A physicist does not need to invoke the Ohm's law to define a potential difference between two points of space which is just the integral of the electric field through any path between these two points, and the electric field can exist in vacuum where no current can flow.

Larger problems have already been pointed out with the quoted claim. A capacitor most definitely can have a voltage across it without having any current flowing in it. An inductor most definitely can have a current flowing in it without having any voltage across is. Ohm's Law tells us only about the relationship between voltage and current in ohmic materials.

 

The issue isn't static versus time-varying electric fields. It is conservative versus non-conservative electric fields.

Of course, for general fields it is conservative versus non-conservative issue, but this was an electronics question : here it is the same as static versus time-varying electric fields issue because a static electric field is always irrotational therefore conservative.

 

Of course, for general fields it is conservative versus non-conservative issue, but this was an electronics question : here it is the same as static versus time-varying electric fields issue because a static electric field is always irrotational therefore conservative.

So you are saying that time-varying electric fields cannot be conservative?

 

So you are saying that time-varying electric fields cannot be conservative?

May be in a configuration where the magnetic field induced by the varying electric field does not contribute to the magnetic flux across the circuit - I don't know if such configuration can exist, interesting question.

In the meantime I found this lecture giving some interesting examples for time-varying fields:
http://inds11.uni-klu.ac.at/lectures/The difference between voltage and potential difference.pdf

 

Oh for goodness sake! talk about going off in tangents. The OP only asked about voltage and potential difference and you all launch in almost a metaphysical discussion about stuff that most likely is over his head and doesn't clarify the situation at all! Keep it simple for learners!