- #1
cianfa72
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- TL;DR Summary
- About the definition of electric potential difference between a battery's terminal and a connection to Earth's ground.
We had a similar thread some time ago. I'd like to reconsider some aspects.
Consider a 9V battery just to fix ideas. The chemical electromotive force inside it establishes an amount of positive charges on its positive terminal and an exact same amount of negative charges on its negative terminal.
Suppose the battery is at 1mt from the Earth surface. The charge distribution on the Earth plus the charge distribution on the battery terminals will be the sources of a static conservative electric field ##E##. Hence one can calculate the elettric potential evaluating its difference for instance between the battery's positive terminal and the Earth. So far so good.
Now suppose to attach a voltmeter between the battery's positive terminal and a Grounded metal rod. The voltmeter will not measure any voltage since it requires a current flow even though its ingress impedence in very high.
In any case I believe there is a voltage difference between them even though a voltmeter cannot measure it.
Does it make sense? Thanks.
Consider a 9V battery just to fix ideas. The chemical electromotive force inside it establishes an amount of positive charges on its positive terminal and an exact same amount of negative charges on its negative terminal.
Suppose the battery is at 1mt from the Earth surface. The charge distribution on the Earth plus the charge distribution on the battery terminals will be the sources of a static conservative electric field ##E##. Hence one can calculate the elettric potential evaluating its difference for instance between the battery's positive terminal and the Earth. So far so good.
Now suppose to attach a voltmeter between the battery's positive terminal and a Grounded metal rod. The voltmeter will not measure any voltage since it requires a current flow even though its ingress impedence in very high.
In any case I believe there is a voltage difference between them even though a voltmeter cannot measure it.
Does it make sense? Thanks.