EEVblog Electronics Community Forum

Electronics => Beginners => Topic started by: joblessalex on September 07, 2013, 08:04:10 am

Title: Path of least resistance?
Post by: joblessalex on September 07, 2013, 08:04:10 am
Simple quick question for the proffessors, if electricity takes the path of least resistance, how come current flows through two parralleled resistors instead of just the lowest one?
Title: Re: Path of least resistance?
Post by: cyr on September 07, 2013, 08:34:35 am
Because "takes the path of least resistance" is just an (over)simplification.

It is approximately true if there is a very large difference in resistance.
Title: Re: Path of least resistance?
Post by: BravoV on September 07, 2013, 08:58:03 am
Imagine two pipes in paralel, one has huge diameter, say as big as a train, and another one as small as a straw, and both connected to the same water source.

I don't think its intuitive to conclude that there must be NO water flow at all in the straw, "no" here means complete zero.
Title: Re: Path of least resistance?
Post by: CalG on September 07, 2013, 02:09:14 pm
The "IF" in your question is the flaw .

Electricity DOES NOT FOLLOW THE PATH OF LEAST RESISTANCE. .................Clear that from your mind.

Electricity flows through all resistances in inverse proportion to the resistance.  (replace with impedance if desired)

Other wise,  voltage divider networks could never be calculated.  (or any balanced circuit for that matter.)

Title: Re: Path of least resistance?
Post by: joblessalex on September 07, 2013, 02:41:02 pm
Whew. Thanks for clearing that up. I always used paralleled resistors and had no idea why they worked! That is a much more reasonable explanation.