That's a really bad way of teaching a subject. Really bad. That kind of teaching is why so many of my fellow students struggled with basic electronics and none of them had a clue about the fundamentals.

Other than the fact that "V" should be "E" that is exactly how Ohm's law should be taught.

 

Why?

 

If you are asking why about “E” not “V” that is just the way I learned it way back when.

If you are asking why Ohm’s law should be taught that way it’s because that is the way Georg Simon Ohm wanted it to be.

 

Like I said before, slight of hand. The calculation of a electric field energy is not an equivalence of charge to energy. Some 'agent' put the charge at that position in space. That action created the electric field energy calculated.

Some 'agent' put the charge at that position in space.
Seems it should be 'angel'...

 

Some 'agent' put the charge at that position in space.
Seems it should be 'angel'...

Yes, it could be an angel or god or the big-bang or ... that created the single isolated electron with its charge in space.

The bottom line is this: https://en.wikipedia.org/wiki/Elect...Energy_stored_in_a_system_of_one_point_charge

The electrostatic potential energy of a system containing only one point charge is zero, as there are no other sources of electrostatic potential against which an external agent must do work in moving the point charge from infinity to its final location.

A common question arises concerning the interaction of a point charge with its own electrostatic potential. Since this interaction doesn't act to move the point charge itself, it doesn't contribute to the stored energy of the system.

The value of 'charge energy' in the electric field of the single isolated electrostatic point charge from some point to infinity is useless in problems about potential/kinetic EM energy or amperage.

 

OMG just went onto wikipedia and look what it says

https://en.wikipedia.org/wiki/Georg_Ohm

"direct proportionality between the potential difference (voltage) applied across a conductor and the resultant electric current. This relationship is known as Ohm's law."


https://en.wikipedia.org/wiki/Ohm's_law

 

When you start using Wiki for electronic lessons, you are doomed to failure, for sure.

 

When you believe that a constant current source produces current you are doomed to failure

 

When you believe that a constant current source produces current you are doomed to failure

Well I never said any such thing, and I learned basic electronics from a professional school where the course was sponsored by Bell and Howell, back in the 70s.

And I would never trust a website that gives only one third of an equation. <<<<<<<<most important point

 

That's a really bad way of teaching a subject. Really bad. That kind of teaching is why so many of my fellow students struggled with basic electronics and none of them had a clue about the fundamentals.

If they only use it, then it is bad. If they use it until they understand it, then it works.

 

Yes, it could be an angel or god or the big-bang or ... that created the single isolated electron with its charge in space.

The bottom line is this: https://en.wikipedia.org/wiki/Elect...Energy_stored_in_a_system_of_one_point_charge
The value of 'charge energy' in the electric field of the single isolated electrostatic point charge from some point to infinity is useless in problems about potential/kinetic EM energy or amperage.

When you start using Wiki for electronic lessons, you are doomed to failure, for sure.

Maybe in this online adaptation of book Paradox-Paradigm you can to find some answers on your doubts...
https://www.paradox-paradigm.nl/?page_id=321

 

What's wrong with the Wiki information other than the fact it's true in this case?

Maybe in this online adaptation of book Paradox-Paradigm you can to find some answers on your doubts...
https://www.paradox-paradigm.nl/?page_id=321

You've really gone off the deep end now with ether theories and other tripe. What next? Links to perpetual motion using static magnetic fields and electrons.

From the same author.
http://www.gsjournal.net/old/physics/cvdt4.pdf

The simple article Stellar Aberration and the Unjustified Denial of Ether proves without doubt that the premise of nonexistence of dragged ether, a specific axiom of SRT, is false. And it states that the Michelson and Morley experiment (1887) disproves only absolute ether and not dragged ether. With dragged ether the exact stellar aberration of any star any time during the year is predicted; undeniable experimental evidence dragged ether exists. The article is refused by physics journals with the argument that the article is not actual, not relevant. How can a paper that disproves SRT ever be not actual or not relevant!

 

When a beginner looks a diagram that shows a circuit's voltages, resistances, and currents, and then wonders: "Hmm, I wonder what would happen if I increased the current here...wait a minute, does the voltage increase or the resistance decrease, or what?!...". The problem of course is that current is not the tunable parameter, it's the result of combinations of voltages and resistances. In any case, the instructor or materials just need to be clear about the true implications of Ohms law.

There is another problem though, and that's the fact that input impedance is rarely discussed at the same time. That can be the source of a lot of confusion as well.

 

Ohm’s law states that with any 2 known values, the third can then be calculated…no more...no less, and all of this talk about what has to come first and stuff is really moot.

 

Ohm’s law states that with any 2 known values, the third can then be calculated…no more...no less, and all of this talk about what has to come first and stuff is really moot.

Because some people want to feel more right than those of us who are right.

 

Oh god what have I started -_-

 

Actually Robin, you did say V=IR was wrong. You also said in your post "V is dependent on I and R is silly" which it is absolutely not. Students should learn that if you double the resistance for a given current the voltage will double. As others said, this is just Ohm's law in practice. I feel sorry for anyone you might teach. The basics need to be explained, but the triangle diagram I mentioned and nicely illustrated by GopherT is one way those I have taught remember how to use the terms.

 

Guys it gets worse. U=IR And where that U comes from nobody knows

 

I've done some decoding of European signal protocols that used U so I looked a while ago for the meaning in traditional circuit theory.

U = Potential Energy
http://whatis.techtarget.com/definition/potential-energy-U

V = Electric Potential Energy Per Unit Charge

If we have 2 volts then
U = 2 V

https://en.wikipedia.org/wiki/Electric_potential_energy#Definition

 

Robin.......an independent variable does not cause a dependent variable. The position of a term in an equation DOES NOT show cause. An equation ONLY shows a relationship..... in reference to one term.

When you solve an equation.......it only shows how all the other terms are related to one term.
It shows how terms follow one another. You make pick any term as reference.

THIS IS WHY MATH CAN NEVER SHOW CAUSE.

There are two prime movers for current. Electric flux and magnetic flux. Both cause current.

Charge is self repulsive. The number one prime mover is the electric field. This causes every charge in the cosmos....to dissolve outward and spread evenly thru-out all space. Every charge has a self repulsive potential of itself.

Every charge has self potential. It is indirectly proportional to it's diameter. When all the little charge pieces fly apart.......a magnetic field is created. When the spreading electric charge field reaches c.........the magnetic field reaches the same strength as the electric........this magnetic field turns all the pieces of charge.....to turn in the same direction. This causes the charge to form a ring.......and the outward velocity is converted to rotational velocity. So the outward charge repulsion is not stopped.........it just rotated. The potential is related to the diameter of the ring. So a charge has self repulsive potential(electric) and a rotational potential(magnetic).

The number of electric field lines NEVER changes on any charge. But we can add magnetic flux lines to a charge. When we do......the added magnetic flux.......compresses the charge ring. This cause the increase in the electric field density because the diameter has decreased. That is increasing the electric potential with induced magnetic flux. So we compressed the same number of field lines by adding magnetic flux.

An electron and a proton has the same number of electric field lines. BUT< BUT< BUT......a proton has a parallel magnetic field and the electron has an anti-parallel magnetic field. OK....what the hell does that mean. That means that when you add magnetic flux to a proton.....the magnetic flux and the electric flux add together and re-enforce each other. The electric potential and the magnetic potential hold each other together....like glue. It seeks and holds a high potential.

However...the electron has a anti-parallel magnetic field. This makes the electron un-compress.....and seek a low potential.

The proton is always compressed about 2000 times as much as an electron. MASS is the electric and magnetic density of the charge. Say that again. MASS is flux density.

This is why a proton weighs about 2000 times an electron.

A charge has a perpendicular magnetic field that rotates and holds a electric field. How much it squeezes it...is the mass. These two fields are perpendicular. If you look at the charge from one direction.....you will see an electric field......if you turn 90 degrees....you will see a magnetic field.

This is why an electric field can move a charge....AND why a magnetic field can move a charge.