- #36
sophiecentaur
Science Advisor
Gold Member
- 28,982
- 6,905
remedemic said:Thanks for the help gentlemen, I can understand voltage alone now, however, I'm having a bit of trouble relating it to resistance at this point.
From what I am reading, a resistor decreases the amount of energy per charge (by converting it into heat or motion through friction), which seems that by definition, voltage would decrease after a resistor, but according to V=IR, and I being constant, voltage goes up?
Could someone clear this confusion up? Thanks again.
I re-read this and it seems you are confusing cause and effect. You need to split the problem into independent and dependent variables. If we're talking about PD (independent), then this is what we start with. Inserting different resistors (independent) across your supply will result in different values of Current (the dependent variable). When you say that increasing the resistance will increase the Voltage, that will only apply if we keep I constant (a different experiment - constant current supply, not constant PD). The way you state it would imply that the height of a (constant head) dam would increase as you take less power from the generators, in the analogous situation.
It is true that, for two resistors in series, the volts across one resistor will increase as its value increases - but only because the current through the circuit decreases and the added resistor gets a bigger share of the supply volts. 'The Potential Divider' is explained all over the place. I don't think anyone who comes across the potential divider will instantly get a feel for it. It becomes very clear, once you have done the simple sums associated with it though.