How electrically common points have same voltage

Thread Starter

ivepoli

Joined Apr 19, 2016
4
Hello,
I read about voltage in capacitor and see that voltage is dependent on distance from the two plates, like gravitational potential energy depends on height.
But how do electrically common points in circuit have the same voltage? Isn't voltage dependent on location in wire?
 

wayneh

Joined Sep 9, 2010
16,164
Right, if there is a conductive path between two points, meaning they're common, any voltage imbalance causes current to flow and the imbalance quickly disappears. Like water seeking a level, only much much faster.
 

hp1729

Joined Nov 23, 2015
2,304
Hello,
I read about voltage in capacitor and see that voltage is dependent on distance from the two plates, like gravitational potential energy depends on height.
But how do electrically common points in circuit have the same voltage? Isn't voltage dependent on location in wire?
Very low resistance along the wire thus very little difference in voltage. There is a difference but your meter could not measure it.
 

AnalogKid

Joined Aug 1, 2013
8,259
Hello,
I read about voltage in capacitor and see that voltage is dependent on distance from the two plates, like gravitational potential energy depends on height.
But how do electrically common points in circuit have the same voltage? Isn't voltage dependent on location in wire?
Yes, but the difference usually is microvolts, too small to measure and way too small to care about.

Technically, most of the time two points in a circuit are connected there is electron flow (current) from one point to the other. But copper is an excellent conductor, and the resistance in the copper connection is so small relative to the energy being moved that the voltage difference is hard to measure. Microvolt meters and micro-ohmeters are designed specifically for these kinds of measurements.

ak
 
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