>> Are you saying the resistence doesn't determine the current? Or are 
>> you just saying that the current can cause the resistence to change?
> 
> If you want to look at it like that, yes, the resistance will depend on 
> what the applied voltage is, rather than always being constant.

You you mean stuff like if you put power through a wire, it heats up, 
and resistance varies by temperature?

> Nobody 
> really talks of "resistance" with such devices though, it's just 
> accepted that V is not linearly proportional to I, and that for any 
> given V you can look up the I from the chart.

Hmm, how odd...

>> Now, see, I always thought electricity just takes *every* path, with 
>> the current being determined by Ohm's law.
> 
> It does, and if use Ohm's law to work out the voltage at a point that is 
> connected to 0V with a 1kOhm resistor and to 5V with a 1Mohm resistor, 
> you will see the voltage is essentially 0V.  OK so it will actually be 
> very slightly above 0V, but that's why there is a tolerance range on the 
> input of such devices.

Hmm... my head hurts now! Heh.

>> So, if you have a high-resistence path from A to B, and then you add a 
>> second, lower-resistence path from A to B, does the current flowing 
>> through the first path change? Or does it remain the same?
> 
> It remains the same.

Oh thank God for that! At least something about my understanding of 
electricity is correct...

The whole "electricity chooses the easiest path" makes it sound like 
when an easier path becomes available, all the current goes down that 
and ignores the other paths! o_O

Post a reply to this message