Help me understand the basics of circuits like volts and current and shit

Eh, I take back that current only ever makes sense in a circuit with resistance, LC circuits oscillate and have a current.

I get the ever so rare water hose analogy. What i want to know is how voltage affects atoms.

Do they just charge the voltage field? do the electrons pass through the circuit with more violence? are the electrons filled with the voltage field? are the atoms filled with the voltage field? does increased amperage means that more electrons are displaced at a higher speed in general or just more at a time?

can we just get back on topic and stop talking about water and shit

>voltage fields
>voltage is a charged force and violence
First, you need to learn what an electric field is (and perhaps what a "field" is in the first place).

Don't waste your time with the "water flow" analogy.

Are you familiar with the concepts of potential & kinetic energy?

yes, and also with how energy transforms into other types of energy.

Recall:
If a ball is laying on the ground it has zero potential energy. If you raise it into the air, it gains potential energy.

If you let go of the ball in the air, the potential energy is converted into kinetic energy (i.e. it falls). If you let go of the ball while it's on the ground, nothing happens, because it had zero potential energy.

The higher you raise the ball, the more PE it has. See picture.

Suppose we were to record the PE of the ball at every point on the picture. We'd end up with a sheet of numbers represented the potential energy of ball would have due to gravity at that point.

This is what we call a "field". It's a mental construct that helps us understand the energies of a system.

See my ghetto mspaint illustration, grey numbers represent potential energy in joules, and also the black arrows represent what we call the "direction" of the field (from high magnitude to low magnitude)

Say you wanted to know the difference in PE between the ball on the second step and the ball on the fourth step? You would simply subtract the field magnitude at the second step from the field magnitude at the fourth step.

This "difference in potential energy" is what we call "voltage" (or, equivalently, "potential")

The "voltage between the first step and the third step" is 20. The "voltage between the fourth step and the ground" is 40. Etc.

Usually, for convenience, we talk about all the voltages in a circuit with respect to a particular point of our choosing. For reasons that should now be obvious, we call that point the "ground".

Forgot to post my shitty drawing

??? My post () is literally pure e&m

So voltage is a unit of measurement of potential energy compared to nothing? but does it measures the potential energy of the electrons or the atoms?

>So voltage is a unit of measurement of potential energy compared to nothing?
It's a measurement of PE with respect to the PE at another point. What we often do is choose 1 and define it as 0 volts. But you've got the idea.

>does it measure the potential energy of the electrons or the atoms?
When we talk about circuits, we are interested in the electrons.

So, what does all this PE stuff have to do with electrons? It turns out charged particles (e.g. electrons) behave like magnets. Like charges repel and unlike charges attract.

Instead of PE due to gravity, we now care about the PE from forces of repulsion and attraction between charged particles.

Imagine you have an electron in space and you drop another electron next to it. They push away from each other. In other words, you can increase the PE of the electron by putting another charged particle near it.

We can make potential energy difference in a wire by adding or removing electrons in one end. Because the two ends now have different charges, one end will be positively-charged with respect to the other. This implies the existence of an electric field inside the wire. The electrons will be attracted to the positive end (or repelled from the more negative end, however you want to see it).

the problem with I is you can't tell if someone typed l by mistake

wow you are so helpfull.

so in a basic way voltage is the potential energy that comes from how the battery charges the electron?

Yes, There's an excess of electrons at the negative terminal.

When you hook the battery up, the top of the battery is positively charged with respect to the negative terminal. This produces a field inside the wire. The electron current flows from the negative to the positive terminal.

Yeah. The Volt unit is defined as Joules/Coulomb. Coulomb is a shit ton of electrons. An amp is a Coulomb/second.

A falling object will gain a certain amount of energy from one place to another. How much is based on how much it weighs.

A charge will gain a certain amount of energy moving from one point to another. If a charge moves from one point at -1V to another at 0V it will gain 1 joule. The battery is like the earth that sets up the gravity field. All it does is make one end "downhill".

A large 12 volt car battery has more cranking amps than a small 12 volt motorcycle battery.
But I don't understand why.

This would be more accurate if you said voltage is the elevation of the river. IE water will flow from high to low elevation

>current only makes sense in a circuit with resistance

Not entirely true. A stream of flowing electrons in the air has current

So more volts make the electrons use the PE to increase amp.

But what would more amperes mean? would it mean that the electron go from one atom to another in a faster way or what? i thought that the energy was already going at the speed of light.

Batteries are more than voltage sources. They can be better approximated by a resistance in series with a voltage source. A car battery has bigger plates so the conduction path is wider. It has a lower equivalent resistance. So when you connect it to a starter motor, which is pretty close to a short circuit, you get more amps.

An ideal voltage source can deliver an unlimited amount of current without a reduction in output voltage. As long as the load is much larger than the equivalent series resistance, you can simplify your life with an ideal source. A starter drawing 60A is a .2 ohm load so you need to rethink things and use an appropriate model.

Going back to the ball analogy:

0 resistance is like picking the ball up to the air and dropping it to the ground. Unimpeded, it falls as fast as it can.

An infinite resistance is as if there's a horizontal surface between the ball and the ground. No matter what, it will never reach the ground.

Any resistance in between can be thought of as releasing the ball on a slope. It will take longer to reach the ground because it must roll down the slope. You can imagine that the shallower the slope, the longer it will take the ball to get to the ground.

This is a somewhat useful analogy for students because as it turns out, you can measure voltage and current at two points, and, with voltage on the x-axis, and current on the y-axis, resistance is exactly the slope of the line between them.

Thanks. Once I bought a used car that had the battery in the back seat. The battery was connected, with cables over six feet long, to the starter. The car started up as normal for a few months but then it stopped. When I moved the battery to under the hood with short one foot cables, the car started up again. Amperage is fickle, and either it flows or it does not flow. Strange to me, anyways.

The velocity of the electron isn't a factor in calculating amps. Amps is Coulombs/second. Coulombs are like mols for charge. An amp means a certain number of electrons are flowing past a certain point in a second.

Electrons don't travel at the speed of light. They have mass so accelerating them to the speed of light would require infinite energy. How fast an electrical signal propagates is a factor of a lot things and I don't understand them all.

One example is transmission lines. A twin lead transmission line with an air dielectric will propagate a signal at about 99% of the speed of light. A coax cable has a velocity factor of about 60-70% depending on on the kind of dielectric used. In integrated circuit design 1ns = 1 foot is a common rule of thumb. I believe the main factor here is the dielectric coefficient.

Electrons actually travel rather slowly. We're generally talking on the order of

Forgot to say, I was confused as hell when I used a multimeter to measure voltage at the starter motor. My meter read very close to battery voltage, with little voltage drop.

Car starting is very fickle. When fractions of an ohm are significant it doesn't take much of a bad connection to throw things off. The resistance of that length of wire comes in to play. The corrossion on connectors comes in to play. If you have a corroded connector you can hit a bump and the movement may cause the connectors to line up where the corrosion prevents just enough surface area to increase the reisistance to where your car won't start next time. If your car won't start and you're stranded, wiggling the connectors is always worth a shot.

So electrons do not go at the speed of light? is it similar to the reason that when you disconnect your computer from the power outlet it will still be on for a fraction of a second?

And what do you mean that velocity of electron isn't a factor in calculating amps? wont that mean that the more amps the more electrons pass through a point in any given part of the circuit? wouldn't that mean that besides becoming a positive charge atom (due to the lack of electrons) the atoms also become charged with negative energy (since a bunch of electrons would go through it at the same time)?

So when you close a circuit electrons go very slowly but the circuit starts up because electrons move at the same time? Gotcha.

Thanks, my car is cranking very slow or not at all, even with a fully charged battery that has been hooked to a charger all week. The voltmeter reads over 12 volts, too.

should just be the resistance overall. Maybe change the wiring to another type, maybe thicker, and shorten the wire lenght.

ok

Garbage thread.

Just go read a fucking book, OP.

This shit is explained in every "Intro to Physics for Babies" book ever printed.

Not that hard to understand.

i already had tried internet and google and books. That's why i ask here.

Your power cable is a transmission line and technically power to your computer doesn't die immediately when you unplug it but the delays is so short you wouldn't see it. Your power supply uses capacitors and they store energy. The can power the computer for small amount of time.

Atoms at a voltage other than ground are charged. This is separate from current. You can have current flowing through an uncharged point. It's not a geometric point. If you were measuring current in a wire you'd be considering through a cross section of the wire. The thing is an area is receiving as many electrons as it gains, then the net charge in that area isn't changing.

In a wire with large amounts of electrons moving in an orderly manner it's not really even useful to consider the electrons in the current as associated with an atom. Metals are conductive because they have some electrons that are losely bound to the atom. It's like one big sea of electrons. When you put a static charge on a chunk of metal the chunk becomes charged. Figuring out which atom has the charge is futile.

I could add that water surface tension is like the magnets part.

>Not that hard to understand
I forget everything I've read within weeks, no matter my level of understanding.

>boo hoo my memory is bad!!!

Reread it then, fag. You don't remember shit you only read once or twice.

Why is it that the people who complain the most about their """""""""""""""""""'bad memory""""""""""""' are the ones who don't understand how memory works?

me too. the only way to remember is to use it on a regular basis.
youtube.com/watch?v=HvR7J4kGV10

>Reread it then, fag
Reread the hundreds of books I've read in my lifetime? The ~20+ hours spent on each? It's utterly hopeless.

why don't you read something that actually has content? grab a fucking textbook and do the fucking exercises for once, you lazy faggot. everything you think you read thus far is NOTHING, ALL SHIT

So from everything that everyone replied to OP i get that electrons can be more or less charged with volts? i thought that all electrons were the same.

>i get that electrons can be more or less charged with volts?
What the fuck?

I didn't read the rest of this thread, but that's a pretty shitty way of understanding it. I trust that nobody in this thread knows what the fuck they're talking about if that's what you got out of it.

For the love of god, read a textbook, or watch some lectures. Don't rely on what a bunch of retards on Veeky Forums are telling you.

So where is the PE of the volts stored into when a closed circuit is active? where are exactly the volts at? the electrons? the atoms? the entire circuit itself? i know that the volts pretty much define the power of the energy charge of the circuit but where is exactly the volts at when the circuit is turned on?

Voltage law, the voltages drop across the assorted resistances. In theory the voltage supply is constant. You can also in theory have a constant current source. A voltage is measured as a potential difference across a load or across the terminals of a battery where the voltmeter is acting as the load. You should really start with Ohms law and go from there because it gets really hairy when you add AC sources, capacitors and inductors.

"voltage" is difference in potential energy. think of it this way: a battery is an escalator, and a circuit is like a slope flowing down from the top of the escalator to the bottom. the "difference in potential" is just like difference in potential mechanical energy here (height)

but WHERE is the potential energy? is it exactly in the electros? the atoms? is it in the electrons that leave the battery?

I got this.
That's chemistry. Valence electrons get excited by the potential and jump to the next atom, the source supplies more electrons. Some people think they move, some people think they just vibrate. Some think they move from the negative terminal to the positive, nobody really knows for sure because magnets.

But that doesn't really gives me an exact answer. Either that or i am just too stupid to understand what you said. The volts are potential energy that goes through the circuit, in the meanwhile losing some volts, and returns to the battery. How do the volts cover the entire circuit? what do they go with? do they stick to the electrons that move through the circuit? do they go through the entire circuit without being attached to the atoms or electrons?

You don't have the fundamental knowledge that is required to understand E&M. Read a proper textbook and ignore the retarded analogies.

1. battery creates chemical instability (think escalator, keeps pushing things up and preventing them from going down)

2. instability tries to solve itself (electrons "fall down the slope", following the least resistance path in the circuit)

3. battery keeps fucking it up

>battery chemically forces electrons out from some atoms creating instability and forcing them to take the route of the circuit back to the battery to stabilize

I get that, pal. What i dont get is voltage.

As previously explained, voltage is potential energy. Potential energy has to be related to an object, right? the battery has voltage or potential energy by creating chemical instability and getting the electrons excited and more charged to try and get to stabilize, so is voltage something that just reads the excitement of electrons in any point to stabilize or does part of this potential energy sticks to the electrons?

it's a difference in something that needs to be stabilized. the electron arrangement is off, and it will try to get back together while the battery isn't letting it

So the voltage is not energy that moves with an object in the example of what i am trying to understand but rather a way to compare how hard the electrons are trying to stabilize back to atoms with no electrons? And since high resistance reduces the flow of electrons it also reduces the amount of volts since more electrons adapt to some atoms and the ones that still try to go from atom to another atom do it with less intensity?

yeah, potential energy is how hard things are trying to stabilize. like when you lift a ball pretty high. it had a lot of "falling down" potential. your intuition for the rest sounds ok.

Right. I thought that the example of the ball falling down and potential energy was that the BALL ITSELF had potential energy. Not that it was an effect of, say, gravity trying to get the ball to fall.

ITT: Pop sci faggots indoctrinating a poor brainlet into their shitty pop sci understanding of physics.

Very fascinating.

>I AM VERY SMART, LOOK AT ME
intuition is very important, and that's what it sounds like. everyone can mindlessly do the operations, brainlet.

I mean, it can't fall if there's something blocking it, and it won't fall if friction is enough to counter gravity, and it'll accelerate slowly if there's friction. take those analogies to resistors, and there you go.

Current is my semen.
Voltage is how hard your mother sucks.
Resistance is futile.

So the more electrons are separated from atoms inside a battery the more they wanna equalize themselves? i thought that electrons would have the same "excitement" regardless of how many of them were excited close to each other.

And if i get it right, the battery uses a chemical reaction to separate electrons from atoms in a one way street to create volts to begin with, is that right?

...

So does a battery ends up empty when the chemicals inside are unable to separate the electrons from the atoms and create voltage? how does the alternator creating positive current helps recharge it then?

Related question to OP: how is it that a coil that has high magnetic field will increase a voltage? and how is it that just like transformers using a thin high looping coil and another coil with less loops will reduce voltage?