Not directed at anyone but to 'water' analogies in general.

Explain electrical circuits in electrical terms.

I agree and I disagree, sorry. As a Professor, I am often put in a position where students may not understand a concept because they cannot see it. It is then our job to put it into a more visual manner and although water is not the greatest analogy to use as you have pointed out, it is the one which most people seem to understand. The garden hose, the water tower, etc, etc. These are all tools Professors use to portray what we are trying to get across. It is helpful if the Professor can explain those concepts in such a way that the student understands. We could use cars and highways, pool balls, etc to visually identify with electricity, but you are correct, the real way is to illustrate something you can't see. And therein lies the problem, just saying.

 

Teaching by analogy is a tool and like any tool, can be the right one for the job or can be misused. This is where the wisdom of the mechanic - the teacher - comes in.

Electricity is often taught in Physics after the concepts of mechanics are taught, things like the potential energy of water in a tower. It's an easier mental leap to understand a few basics of electricity, like the units of measure, when you can draw the parallel to familiar topics. The water analogy has fallen into disfavor even in this setting, though, because it later hinders these same students when they have to deal with inductors, transistors, current in circuit loops and so on.

Personally, I think it's VERY useful for helping a student grasp a few concepts - like the distinctions between voltage, current and power - as long as the student is also taught that it is only an analogy and cannot be used in every problem, so they don't become the baby with a hammer.

 

Not directed at anyone but to 'water' analogies in general.

Please don't use water analogies for beginners to describe electricity IMHO. I know it's tempting to do as people assume others understand hydraulics when they don't have a basic understanding of electricity. An analogy is good when people actually have a deep understanding of both subjects and use the analogy to explain a process in one as analogous to the process in another.

Explain electrical circuits in electrical terms.

In general I disagree -- but not without points of agreement. I don't think that you need a deep understanding of both subjects in order for an analogy to be useful, especially since the whole idea is to use the analogy to help develop a deeper solution of one of those subjects. But you do need a sufficiently deep understanding of the field that the analogy is drawn from in order to understand the parallel being drawn. As an example, most people can intuitively understand a water analogy with KCL by picturing a stream of water that divides into several channels and then comes back together and use that to grasp the notion that the electrical current entering a junction has to equal the sum of the currents that leave the junction and also the notion that we don't need to know the details of the parallel paths to know that the current entering the point where the parallel paths begin has to equal the current leaving the point where the parallel paths come back together. But using water pressure analogies for voltage requires a better understanding of hydraulics than most people would have (though most engineering students should have the necessary understanding because of the Physics I prerequisites that are all-but-universal.

 

Not directed at anyone but to 'water' analogies in general.

Please don't use water analogies for beginners to describe electricity IMHO. I know it's tempting to do as people assume others understand hydraulics when they don't have a basic understanding of electricity. An analogy is good when people actually have a deep understanding of both subjects and use the analogy to explain a process in one as analogous to the process in another.

Explain electrical circuits in electrical terms.

How 'bout marbles packed end to end in a hula hoop?

 

Also, the holes in the breadboard are connected as follows...

 

How 'bout marbles packed end to end in a hula hoop?

Apparently only if the person already has a deep understanding of both electricity and marbology.

 

As an example, most people can intuitively understand a water analogy with KCL by picturing a stream of water that divides into several channels and then comes back together and use that to grasp the notion that the electrical current entering a junction has to equal the sum of the currents that leave the junction and also the notion that we don't need to know the details of the parallel paths to know that the current entering the point where the parallel paths begin has to equal the current leaving the point where the parallel paths come back together.

The problem I see is the mental picture of a beginner that's built from that current analogy. We start to create a pattern that relates current/electrons as an energy force of electricity that branches off, does work and reconnects in a loop. The problem with that analogy is that it's false and completely misleading. The energy flow of electricity is a system process with the actual direction of current flow being arbitrary. The use of water to understand electricity in general is even worse because eventually they will have to relearn something that should have been taught correctly in the first place where basic (qualitative) information about charge, electric and magnetic fields and energy replace water.

http://www.abc.net.au/science/articles/2014/02/05/3937083.htm

 

You should get a multimeter. The multimeter will allow you to get a better picture of what is going on in your circuit.

With the multimeter measure the voltage on each side of the LED. This will make clear the voltage difference across the LED. It is generally faster to learn by a combination of reading and experiment.

 

I agree and I disagree, sorry. As a Professor, I am often put in a position where students may not understand a concept because they cannot see it. It is then our job to put it into a more visual manner and although water is not the greatest analogy to use as you have pointed out, it is the one which most people seem to understand. The garden hose, the water tower, etc, etc. These are all tools Professors use to portray what we are trying to get across. It is helpful if the Professor can explain those concepts in such a way that the student understands. We could use cars and highways, pool balls, etc to visually identify with electricity, but you are correct, the real way is to illustrate something you can't see. And therein lies the problem, just saying.

People do understand open piping systems (open facet, water comes out and down the drain) but do they really understand closed loop systems as an analogy to charged particles moving around the circuit in response to energy flows outside the piping?
I think the way you deal with the problem is to tell them to forget what they think they know about electricity and to prepare to understand what the science of electricity is all about. Believing in things you can't see seems easy for most humans.

http://www.matterandinteractions.org/Content/Articles/circuit.pdf

 

People do understand open piping systems (open facet, water comes out and down the drain) but do they really understand closed loop systems as an analogy to charged particles moving around the circuit in response to energy flows outside the piping?
I think the way you deal with the problem is to tell them to forget what they think they know about electricity and to prepare to understand what the science of electricity is all about. Believing in things you can't see seems easy for most humans.

http://www.matterandinteractions.org/Content/Articles/circuit.pdf

Forgive me if I am wrong but I am starting to see a pattern with your answers. They all have some sort of backup from the Internet and I applaud your enthusiasm in your research, but it is just that. I stand in front of 30 students every day and although I teach Automotive/Truck/Coach and mainly DC, I still have to find a way to reach every one of my students at the same time. Some get it right away, some get it with a water analogy, some get it using cars and highways. The object of the who;e thing is to use an analogy that works for that person because we all learn in different ways. When I think they have it, we back it up with hands on. Teaching strictly over the Internet is easy. Just look at all the foolishness on Youtube. There are some very good instructors and some very poor ones. Some I learn from, some I have no clue what they are telling me. It's all in the delivery and being able to use every tool you have to drive the point home. I'm not saying I'm right, I just know what has worked for me and it is not the only tool I use to get from A to Z. I learned by water and I am no hydraulics major, but I got it. I also learned hydraulics, by other methods, pneumatics as well. All in the teacher and how he makes you see something. Marbles in a hula hoop, whatever floats your boat. It works. It's like a transmitter and receiver. Reciever won't get it if it ain't tuned in!

 

I think you get people to understand electricity by handing them a box of batteries, bulbs, motors, wires, switches and ask them to make a bulb light and a motor turn. Then make two bulbs light, then make two bulbs light the same brightness ( because they almost always connect them in series the first time).

Make the connect a switch. Make them connect a three way switch (amazing how cheap house 120 v switches are vs 12 volt switches).

Use 1.5 or 3 volt bulbs for everything.

Stay away from LEDs until they understand electricity, then you can move on to electronics, LEDs, ...

 

Forgive me if I am wrong but I am starting to see a pattern with your answers. They all have some sort of backup from the Internet and I applaud your enthusiasm in your research, but it is just that.

I hear you but this is an 'electronic circuits' forum where hopefully some of the future engineers will get their first start. I teach everyday but not in a formal classroom and I've spend far too much time retraining recent grads of the current electronics tech schools on simple field theory for their jobs. Yes, I've researched for better ways to explain to them how to understand complex systems that don't just involve current flow in wires but have modes of EM energy generation and control (like RF Linacs or Tandetrons) that involve knowing some simple relationships about charge, fields and energy that give rise to currents and voltages but usually I get a blank stare and if I hear anything about water, cars, marbles, buckets, trains, ropes or pipes it usually means even more explaining to do.

Rant mode off.

I did find the Mouse - Cheese analogy to be good.
http://www.regentsprep.org/Regents/physics/phys03/bmousechz/default.htm

 

I think you get people to understand electricity by handing them a box of batteries, bulbs, motors, wires, switches and ask them to make a bulb light and a motor turn. Then make two bulbs light, then make two bulbs light the same brightness ( because they almost always connect them in series the first time).

Make the connect a switch. Make them connect a three way switch (amazing how cheap house 120 v switches are vs 12 volt switches).

Use 1.5 or 3 volt bulbs for everything.

Stay away from LEDs until they understand electricity, then you can move on to electronics, LEDs, ...

Ten years or so (probably more, by now) a group at Harvard did some studies on how well students actually learn concepts and they looked at a number of groups ranging from elementary school kids to college graduates. The results were pretty amazing -- and depressing. They went to the commencement exercises at MIT and asked various engineering graduates (some EE and some not) if they could take a battery, a wire, and a flashlight bulb and make the bulb light up. Almost all of them said they could, but when given a battery, a wire, and a flashlight bulb a surprisingly high percentage of them, including many EE graduates, couldn't actually do it.

 

The YouTube video is here.

I suspect this was Harvard punking MIT. For one, many commenters say they recognize the area in the video as Harvard. It was probably just some posers from Harvard.

However, there does appear to have been such a study done, but it was all graduating seniors, not just engineering majors. I could entirely believe that graduating seniors in general would not be able to do this. Most the people I knew in college were about as dumb as a garbage man. They were stoned or drunk everyday by noon. Cheating was rampant.

 

I have a friend that graduated from MIT and he said that it was, indeed, MIT.

Yes, they did ask a sampling of all graduates, but I was only focused on the engineering graduates (and it's been a long time since I watched the video or read the study, which is very interesting). They were picking on MIT a bit, but they included Harvard in their study as well (but tested different subject areas, which I forget) who did just as poorly. They made a couple of very interesting videos of their work, one of which was asking middle school students, after having been through lessons that talked about how we see objects as the consequence of light reflecting off the object and into our eyes, if they would be able to see in the dark if they were in a completely sealed and darkened room and allowed to stay there for a long time to let our eyes fully adjust. Many of them said that they would and the reasoning common to many was the notion that how we see is that light comes out of our eyes and bounces off of objects.

They did a similar study to the flashlight bulb experiment with either middle school or high school science students that had just been through a lab that included making circuits to light the bulb but that had used lamp fixtures and switches that had been screwed down to a board and now they were being asked to do the same thing but without the fixtures and many of them couldn't because what they took away from the lab was that the fixtures were a required part of the circuit.

 

Good video, especially the point made at 1:57 but instead of lighting the lamp it's how the circuits works and how electricity 'moves' and what direction.

Another training research link I use.
http://www2.warwick.ac.uk/fac/sci/physics/current/teach/module_home/px263/lectures/sefton.pdf