What Does Negative Voltage Really Mean in Different Electrical Contexts?

[Red_CCF]

You are not thinking this through clearly. It absolutely must change for one and not the other, regardless of the direction of the current. Say you label one terminal of the voltmeter "A" and the other "B" and say that you label one terminal of the battery "a" and the other "b".

Now, let's say that you put the voltmeter on your left with "A" up and "B" down and the battery on your right with "a" up and "b" down and you connect "A" to "a" and "B" to "b". Now, you will have a loop, current will go around that loop either clockwise or counterclockwise. If it goes clockwise then current will go from "a" to "b" through the battery and from "B" to "A" through the voltmeter. If it goes counterclockwise then current will go from "b" to "a" through the battery and from "A" to "B" through the voltmeter.

Now, we flip the voltmeter so that "B" is up and "A" is down, and we connect "A" to "b" and "B" to "a". We again have a loop and current will go either clockwise or counterclockwise. If it goes clockwise then current will go from "a" to "b" through the battery and from "A" to "B" through the voltmeter. If it goes counterclockwise then current will go from "b to a" through the battery and from "B" to "A" through the voltmeter. Either way the direction of current through one and only one must change.

I apologize for being so slow but I just can't seem to wrap my head around this for some reason. The part that I don't quite get in your explanation is the part where the current goes through the battery. I was told that current never goes through the battery but from positive to negative terminals through the wire.

 

[Dale]

The part that I don't quite get in your explanation is the part where the current goes through the battery. I was told that current never goes through the battery but from positive to negative terminals through the wire.

You were told wrong then. Current always goes in a complete loop, that is why we use the word "circuit" to describe electrical devices. This also relates to our https://www.physicsforums.com/showpost.php?p=2311338&postcount=20" where we specifically talked about the current through a battery.

 

[Red_CCF]

You were told wrong then. Current always goes in a complete loop, that is why we use the word "circuit" to describe electrical devices. This also relates to our https://www.physicsforums.com/showpost.php?p=2311338&postcount=20" where we specifically talked about the current through a battery.

Oh I think I know where my confusion arises from. I was thinking about the flow of electrons which doesn't travel through a battery but I did not consider the electrolytes as charge carrying current as well.