That's just like the difference between electricpotentialdifference and the electric field.
2
The electricpotentialdifference between these two ends is 9 volts.
3
This happens not at a certain electricpotentialdifference (voltage) but at a certain electric field strength.
4
The common method is a device that produces an electricpotentialdifference when light hits it -you know, solar panels?
5
I'm going to give you (and them) a super basic introduction to measuring electric current and the electricpotentialdifference (usually called "voltage").
6
In this example, there is a charge of +Q on one plate (and -Q on the other) with an electricpotentialdifference of ΔV.