My favorite gripe is use of the phrase: "Electricity always takes the path of least resistance". This implies that electricity will not take the longer path.
First gripe: electricity is not intelligent and cannot decide which way to go.
Second gripe: in a parallel path electricity flows through all paths regardless of resistance, and the flow is calculated by ohms law.
Electricity takes every path, not just the "path of least resistance"!!!!!

Isn't this where Kirchoffs Law would come into play?

I think this is a direct reflection on the idea that humans tend to think that physics work the same way their brains do. Which in my case I can confirm.

Many humans try and take the path of least resistance only to find they are often forced to take other paths.

If you truly believe electricity takes the "path of least resistance", then I challenge you hold onto the GEC at your service during a lightning storm. Hold tight!

Kirchoff says all the current going into a circuit comes out somewhere.
Ohm says it will come through the various paths in inverse proportion to the resistance/impedence.
Dean is saying it will take all paths available.
These are all true statements.

Not sure what the gripe is, electricity will take the path of least resistance. It may take others also. Won't the path with the least resistance have the highest current available also?

The problem is by saying electricity takes the path of least resistance, it is implied electricity will shun any other paths.
A shock hazard exists even if you are a higher resistance path to ground than the equipment you are working on.
It would be far better IMHO to say "electricity will take any and every path".

Just ask the Con Edison POCO. Seemingly every few months or so another person (sometimes a pet) gets shocked and is either injured or killed. Electricial current HAS to return to it's source somehow.

I agree with Earl, this subject is also a pet peeve of mine.

I always point out to people that post 'electricity takes the path of least resistance' that it also will take all available paths.

IMO it is dangerous to think of electricity taking only the 'easy path'.

I think this probably goes hand-in-hand with another great electrical myth:

"Electricity always tries to return to ground."

Sorry have to disagree with you on this one.
I think the statement is a very good one from a beginner’s point of view.

Put yourself in teacher’s shoes and try this

Explain current flow being negative to positive?
Describe what an Amp actually is?
Describe alternating current?
How does a fuse work?

How many pages of explanation did you write? Where did you start? Where did you stop your explanation?

The amount of explanation is relative to the level of understanding required.

We need to nurture our students not bamboozle them with science. Start too deep an explanation and you will loose the student and he will not come back. He may be there physically but he is not interested any more. You need to get them hooked on the subject, start your explanations of simply and as understanding grows, expand on your explanations.

I have looked at other forums on the net and I like this one best. The contributors come across as mature, experienced tradesmen. But please do not loose sight of your roots. We just as all had to learn to walk, learn to drive a car, we all were apprentices once upon-a-time.

Ken how is it complicated to tell students electricity will take all available paths?

You don't have to say more than that. No need to explain why to a beginner only that it does.

IMHO teaching them "electricity takes the path of least resistance" is just something they will have to 'unlearn' later.

Besides leaving them with the impression that it only takes the least resistive path is IMO dangerous.

Bob

"Second gripe: in a parallel path electricity flows through all paths regardless of resistance, and the flow is calculated by ohms law.
Electricity takes every path, not just the "path of least resistance"!!!!!"

And a darn good gripe, a good example is, years ago the meter socket neutral was not bonded, you had to install the bond jumper if needed, we used rigid pipe with service installations, back then, and we bonded the conduit.

Now most of the meter socket neutral lugs are bonded from the manufacture, ok for PVC or service cable, but think what you have when you use rigid with one of the bonded meter pans?

Good topic!

I also agree with Earl.

Ken, when teaching beginners I don't see any reason not to teach this, after all it is a simple function of Ohms Law which must be taught to and understood by the student.

In most instances this is actually how a GFCI and RCD (however I'm not hands on familiar with the latter) function in their design.

Roger

SOmeone help me out with a real life situation where using
this familar saying will hurt someone??

just curious, does anyone know where the saying" the path of least resistance" got started? I heard it in electrical school, and it was confusing when I got into more advanced concepts, looking and circuit diagrams and trying to apply that statement to what I was looking at. The other interesting concept mentioned earlier was electricity will try to return to ground. I was taught this as well, and it took a few years and a lot of time on ECN to get the whole " return to source" thing to sink in.
So remember, be careful how you explain these concepts, they are complex, but they are more confusing when the foundation information doesnt allow the student to understand the more advanced stuff.

It peeves me somewhat, too.
Learn it once, Learn it right.

Sometimes things are more easily understood by beginners when it's demonstrated by something non-electrical. Fill a cup with water, put a big and a small hole in it. Water flows out both of them. More out of the big hole than the small one. The concept is no more complicated than that.
Spinning an Ohm Wheel around in front of their eyes right off the bat will just make them dizzy.

I taught a 9 year old once about switches, wire sizes, and circuit breakers with a trail of ants that were walking on twigs, just replacing the word ants with amps. She learned the basic ideas in minutes, even understanding a crude 3way made of twigs. I was elated

I wish some customers could learn as well as she did.

[This message has been edited by electure (edited 12-06-2006).]

I'm not usually one to get hung up on this detail; maybe that's because I first learned "Murphy's Laws for Electricians."

These laws might read something like this:
1) If you test every wire but one, that one will be hot.
2) If you can grab any of several wires, you will grab the live one.
3) A $1000 TV set will sacrifice itself to protect a 5 cent fues.
4) Electricity is a malevolent thing, and will endlessly flow throug all the wiring, looking for a chance to zap you.
5) Expensive new wire cutters are better at finding live wires than old rusty ones.

And don't forget:

It will be the last circuit breaker you try after trying all the rest.

And why do people say: "it was in the last place I looked". Of course it was in the last place you looked because that's when you stopped looking!

You can always say that most electricity takes the path of least resistance. Conversely, the least electricity takes the path of most resistance. The least may be too much if you just happen to be that path least traveled.
Joe

Line work, where someone is using a grounding set for protection. The set has to be sized adequately for the fault current available and placed correctly to protect the lineman. To give that worker the impression that "any" type of ground applied in "any" manner will save him "because it takes the path of least resistance" would get him killed.

Is the 'Nailed by Neutral' thread? (The one that doesn't exist yet)

I too hate the 'least resistance' idea, and often tell people to rethink it as a water analogy. Every available path, and think of wires as garden hoses.

BigB, I tell people that the problem will always in be the last place I look while troubleshooting..... It always is!

I assume linemen know their job and understand what it takes to make themselves safe while working. I also assume electricians unserstand current will flow in any path it can.
So how is this saying making the world unsafe??

Let's say a receptacle is feeding an 1800-watt load. That's a resistance of 8 ohms (at 120V).

Now assume that you put one hand on the neutral terminal and the other on the hot terminal of the receptacle. Your hand-to-hand body resistance will be many times greater than the 8 ohms of the load, but would you still believe that electricity will only take the path of least resuistance?

Fair point trekkie.... it took me a while to get to grips with earthing arringements here in the UK.

electure. I am all for making things as visual as poss. It is hard to explain things that you just can not see (we dont have many ants in scotland....the haggi keep eating them )

Reno true funny but true

The one saying I was told by an old tradesman and I dont think anyone can refute is
"Electricity is a good slave but a bad master"

Kenny

A very unsafe assumption. An awful lot of people learn from the guy, that learned from the guy, that learned from the guy before him. This applies to linemen and electricians. It's important that those who teach, teach correctly.
Now, having said that, I agree it'a a fine point to argue this phrase. However, when someone's new to a technology, it's not always predictable how they will interpret a phrase. Better to be safe than sorry.

This is a really interesting thread. I have a question to ask. Since electricity does take every possible path that it can, why is it that one can't (or doesn't) get shocked when in contact with the neutral of a circuit that is off in an electrical system with other circuits that are still under load. Wouldn't another circuit under load and returning it via the main neutral actually back feed the neutral of the dead circuit a bit? Or is the answer to this have to do with the fact that the neutral is grounded?

Just wondering here... sorry if the question is confusing.

There is always a potential difference from neutral to ground. Often barely measurable. Depending on a wide range of factors as to how much. If the neutral wasn't grounded, there would be a much larger potential difference.

See the "nailed by neutral" thread...

Grounding and Bonding works by that very principle. The voltage available to shock you is equal to the voltage drop between the point where you grab the grounding conductor and the point where your feet are touching. This voltage will be small if the resistance is small, which can be acomplished by establishing an equipotential grid for your feet, and bonding it to any exposed grounded surfaces that may have voltages.