Electric Potential, Current, and Resistance
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- Опубликовано: 11 апр 2017
- Whenever you plug something into an electrical socket, don't you wonder what's going on? Well you should, as it's pretty neat. What is electricity made of? How did we figure out how to harness this power? Let's take a look at electric potential, current, and resistance.
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Just want to put in a thankful comment, because of your analogies to gravitational fields. The position of a particle in an electric field compared to the position of an object in a gravitational field was the clearest thing i've heard in a while!
Damn! Physics needs to be Daved!!!
You are awesome!
#ScienceDaved
i’m from 2024
No way me too 😂
Is professor still Alive 🥲
Mind blown when you explained potential energy from electric field analogous to the gravity field. Now i picture electrons falling from negative terminal to a positive terminal and force being applied to charge the battery like aaplying force to lift something up against gravity!
I swear!! So much better than most explanations which are isolated to charged particles and difficult to relate.
@@brankelly1921
Honestly, this one falls in line with the math even better than the water explanation!
pebre79
Well it _is_ somewhat said to be how Einstein understood it. 😁
@@ivoryas1696 The water example would have been better if he used a waterfall in the example because its falling from a higher point (+ charge) to a lower point (- charge).
What is electric current?
What is electric current? Electrons flow in a conductor?
How do electrons flow in a conductor? Like many cars driving down the highway? Or is water flowing in warer pipe? What is a highway in a conductor? What is the water pipe in the conductor? Why don't electrons flow to the positively charged nucleus? What magic keeps electrons away from the nucleus?
Is the speed of electrons flowing in copper wire the speed of light? If not, how could electricity travel at the speed of light? If so, how can electrons accelerate at the speed of light?
In fact, Atoms are not made from charged particles as scientists told.
All atoms consist of indestructible, electrically charged multiple layers hollow sphere and internally charged solid sphere. Outside each atom is a layer of negatively charged liquid that scientists mistaken for electrons.
This negative charged liquid attaches to non-metal atoms due to their outer layer is positively charged and floats on metal atoms due to their outer layer is negatively charged. The floating liquid of a conductor conducts electricity.
Electricity is flow in conductor
instantaneously, similar to hydraulic fluid flow through hydraulic systems.
The voltage of the electricity is proportional to the speed at which the floating liquid moves.
YOU ARE AMAZING. THIS VIDEO SINGLE HANDEDLY ANSWERED THOUSANDS OF QUESTIONS IVE HAD. THANK YOU SO SO MUCH. YOU HAVE NO IDEA THE AMOUNT OF CONCEPTS I CONNECTED RIGHT NOW! THANK YOU DAVE, YOU ARE AN AMAZING PROFESSOR!!!!!!!!!!!!
I have always liked Pro. Dave’s explanation so far, everything of his videos is perfect, the illustrating pictures, the written and verbal explanations are very easy to understand, his voice is clear, the examples are interesting and fun. I admire you. Best wishes to you.
Nice video. Nice juxtaposition of gravitational Potential Energy (PE = mass X g X height), and electric Potential Energy (PE = -charge X E X displacement).
This is mind blowing, thank you!! Also - we need an engineering series! There's a lack of good, english explanations in that area on yt!! :)
Super helpful as always. Thank you Professor Dave!!
That's Awesome Thank You Proffessor Dave
Marvelous, mind blowing concepts
"He knows a lot about the science stuff, Professor Dave Explains!"
the greatest sound in existence
Hi Prof. Dave! Thanks for every single video, you helped me a lot and I really look forward on the engineering course. Please do an engineering approach in thermodynamics T.T Appreciate you so muchh!!
looking forward to future content on circuits and engineering!
You are awesome and brilliant sir. Your tutorials helped me a lot.
Truly great explainment thanks a lot for posting such a great videos u r the maestro off physic thanks again🤗
Thank you so much😭😭. We have a test tomorrow and this really helped. God bless
wish you could do more in depth problems regarding electric potential. great work anyways !
Dude! You're awesome!!!
That was very good explanation.
Very nice ,thank you Professor
OH MY GOD THANK YOU IVE FINALLY UNDERSTOOD
Amazing stuff
Can you please make a video about gauss's law and surface charge density
YOU ARE GREAT
Can't wait more for an engineering course o_o
@Froster Freak Why
I'm 29 yo guy who is willing to study engineering back to square one at this age. I haven't learn any physics in my high school and university. Thank you! Now everything is getting much clear for me, you are my hero!
Nice job!
The way school taught me electric currents made me believe that current IS potential diff/resistance and potential difference IS the product of resistance and current
It took me 2 years later (now) to realise those were just formulas derived from the relationships I and V had in order to describe resistance - and that in fact, both I and V are completely different things on their own
Gotta love the school system and its abilities to confuse and misguide learners!
Awesome video!!!
It's unique like always n the best
I am studied 11th and 12th class...But I didn't practically know what is voltage...
Professor dave ur really my hero ever teached like this.....
May god bless you....
Me:"Oh Jesus help me i dont understand it..." -"Ok ask my collegue))"
Your English is shitty as fuck
Waiting for that engineering series :3
dave you are a lifesaver
excellent
man.
good job man
Omg...it's really good ..take love sir ..i am from Bangladesh..😍
Professor I like your videos a lot
They are really helpful.
Can you make a video on how actually a dry cell works.
Thanks man
Sir you are great
good stuff
Engineering Branch? That would _be _*_great!_*
I understand that you'd like to elaborate on Chemistry, and work on Italian and Zoology among others. I myself will probably watch _all_ of those at some point; just... don't forget us, okay Dave?
Have you considered adding some lectures on electric circuits?
Amazing sir
paul bartrum.....i got it... real thanx
I have always wondered as a science student so thought I wud probably ask from you that... can the positive charges produce current on their own or its just that they become positive by loss of electron. n electrons are present within them n they are ones producing current by their movement n it seems current is because of positive ions...
Current is defined as the direction of flow of positive charges. But in a real circuit with metal wires it's only the electrons (the negative charges) that move, the atoms stay where they are. Thus if you have a current flow of 1 amp in a certain direction, the actual flow of electrons is in the opposite direction.
Interestingly, your nervous system operates by generating voltage spikes that move along the nerves, and the way it does this is by moving around positively charged sodium ions. While this works, it's extremely slow compared to the voltage spikes in, say, a modern CPU (something like a million times slower).
nice job
Thank u sooo much!
"Resistance is the ability of a material to opoose charge flow"
This means the magnitude of charge not charge particles. Okay!
Reason: you can take an example.
There is a circuit with a 4V battery and 1ohm resistance wire. The current that flows through it is 4amp.
What if we double the area of cross section? We can treat it as two separate resistors of 1ohm resistance added parallel therefore giving rise to 1/2 ohm resistance in series.
You may notice that in this case motion of any charge particle is not affected. Means their velocity is still the same. But the amount is changed.
Current isn't the same thing as the velocity of any individual charged particle. Current is the aggregate flow rate of the charges. It could either be due to a large number of charges or a high speed of the charges, or both. Twice the population of charges flowing at half the drift velocity will still generate the same amount of current.
can you tell about static electric field
You just made me understand electricity
It sucks when teachers don't teach and someone like me actually wants to learn. Oh well, lemons outta lemonade, thanks Professor Dave!
Thank you
principle that the electric current passing through a conductor is directly proportional to the potential difference across it, provided that the temperature remains constant.
Sir in this definition last sentence is provided that the temperature remains constant . So if temperature is not constant how will it effect the circuit ?
Listen, if temp increase, resistance increases so I hope u can relate it!
@@vachansinghrajpurohit6310 yes
@mihir good question though
Thank you sir
Paul bartrum thanx for taking interest... so you are saying that positive charges do produce current as in nervous system but its very very low... n current produced due to electron movement is way faster n that's how average electric circuits operate...
Yes, the signals in the nervous system are both low voltage (approximately 0.1V) and low current (perhaps microamps?) But electron movement in a wire is actually very slow: much less than a millimeter per second. It's the voltage or the "signal" that moves extremely fast. To understand this, imagine you have a long pipe filled with ball bearings. Now push on a ball bearing at one end. Notice how the ball bearing on the other end moves almost instantaneously? Even though the ball bearing you pushed moved very slowly, the "signal" travelled along the pipe very quickly. In fact the speed of a push is the speed of sound, which in steel is about 6km/sec. In the same way, the electrons in a wire also move very slowly but voltage changes propagate through the wire extremely quickly. In thick copper wire they can propagate at about 280,000km/sec, almost the speed of light!
I'm confused between taking up electrical or civil engineering. But I became so fascinated with electrical stuff though Im not good really at it.
عظمة يابوعمو 3>
Can you please show the charges in a p-n junction? The built-in potential, ().7 V for silicon), produces a drift current, offset by a thermal generation of electron-hole pairs. Can you please show how a bipolar transistor works? The forward biased emitter-base injects charge into the base, where it *diffuses* to the collector. MOSFETS are easier to understand , but the BJT has charge diffusion at its source.
sorry i'm not so good with that stuff! one day i will learn it and do a whole course on engineering.
Haa
bless you and your magic explainy words, magic man, may both sides of your pillow be cold and your tunes be bangin
Suppose we have a battery of 6V . And I know that every 1C of charge that are present in the negative terminal possess 6j of P.E What about the electrons in the conductor? Are these electrons present in the conductor also get 6J of P.E for every 1C of charge? When it's connected with a battery.
For historical reasons, we treat the flow of charges as if it were hypothetical positive charges, and put aside the fact that it is really electrons flowing the opposite direction. 9 times out of 10, it doesn't ultimately matter which charges do the flowing. It delivers the same effect either way. It usually is the electrons that do the flowing, because the protons are bound within the nuclei of the atoms by the strong nuclear force, and would change the identity of the element if they were to move to a different part of the circuit.
When the sign convention of charges was originally set, we didn't know that the charges that did the flowing were actually negative charges. And we have the body of knowledge and conventions that are all based on this ignorance, and it is not worth the effort to change everything to correct for this "mistake"
Given a battery of 6V, with 1 Coulomb of charge supplied by it in a given period of time, this means that you will have -1 Coulombs worth of electrons (i.e. 6.24*10^18 electrons) flowing from the negative terminal to the positive terminal, and they will carry 6 Joules of energy from the battery to the load.
Sir you are the best teacher and your hairstyle is cool
professor dave is a certified pogchamp
these videos are like summaries of what we have already learned.
Thanks
Please introduce engineering course sir!
You are intelligent person 🙂
Ure great ...
Good
That moment where you got the intro stuck in your head...
Mr. Dave I have a Question based on *Electricity*
Hi sir!
Plz tell me what is the real meaning of potential at a point plz
Given a conservative force (gravity and electrostatics are two examples), there is a corresponding potential energy at every point in space, that a given body participating in this force will have, by virtue of its position relative to the other bodies that are causing this force field. The work a conservative force does, when moving an object between two points, is independent of the path. As a result, the difference in potential energy is used as a shortcut for calculating the work done by a conservative force. We don't need to care about the details of the path we take between two points, we just care about the potential energy at the origin and the potential energy at the destination, given that it is a conservative force.
When we divide this potential energy by the property of matter enabling participation in this force, we get the concept that is called potential. Potential in general = potential energy divided by participation property of matter.
What the heck do I mean by "participation property of matter"? Easiest to explain with examples. In the case of gravitation, mass is the participation property of matter. The more mass an object has, the more it participates in gravitation. In the case of electrostatics, electrical charge is the property of matter. The property of matter that enables an object to contribute to this force, and be acted upon by this force, is the "participation property of matter".
@@carultch you sound smart
Hello, excuse me professor... can you tell me what software do you use for creating your videos?. I am a professor too, but in México 🇲🇽. I need to explain this topic to my students (in Spanish). I would like to recreate your videos and explain them in classroom. And other topics... I like the way you present. Kind regards.
Adobe after effects
@@ProfessorDaveExplains thank you 😊
What is the SI unit of charge
coulomb
somtimes i wish that you studied coupls therapy ,so i can see the international devorcing indecator = 0
انت شرحك رائع
@ 1:17 you forgot to include the delta symbol to indicate the "change" in electric potential energy.
other than that great explanation professor!
2.27min. why is there positive charge moving? do 😒protons move in a wire?
Protons are bound in the nuclei of the atoms, which themselves are rigidly fixed in place in the crystal lattice of anything solid. Protons would need to change the elemental identity if they were to become free from their nucleus. Plus, electrons have a lot less mass, and are a lot easier to move with a given electric field. As a result, electrons are the most common charge carrier in matter familiar to you.
In metal conductors, electrons will be the charge carrier. Inside a battery, there are actually both positive charge carriers and negative charge carriers coexisting, as both kinds of ions are exchanged across the electrochemical cell between the terminals.
@@carultch yep , thanks. in the family there are three generation . do you think there will be new generation? after some time , 4 forces might break into more then 4 . i can feel it verry verry soon only after few trillion,zyllion,.....
Prof Dave,
humans have a charged body, yes? If a street light is not fully on. As I get closer the light starts getting brighter then right when I am under the light and light is fully on. But as I walk away the light starts flashing again.
What is your take on this.
No, bulk matter is electrically neutral.
🔝
I watch any add just because of you
Can I?
So in other words electric current is the quantity of electrons passing through an electric circuit per unit time
Who else has never noticed his tatto on his arm? 😅😂😅😂
كنت عندي مشكلة كبيرة في فهم الظاهرة الكهربائية بشكل عميق و تأكدت انني كنت على حق
لا يمكن فهم الكهرباء عن طريق المقاربة الهيدروليكية الغبية لانها لا تصف الكهرباء بشكل دقيق
للتمكن من فهم الية عمل التيار الكهربائي يجب فهم ميكانيكا الكم المتعلقة بسلوك الالكترون.
Hello
2:55 that’s a lie only electrons generate electricity??
That's not a lie. Charges of both signs can carry electric current. For instance, positive sodium ions in nerve cells can carry current. You also will have current with antimatter positrons.
Sounds like a textbook
Thank you science Jesus!
why does it feels like Jesus Christ is teaching me? hahaha thanks, professor dave for this!
here i come with an extremely stupid question but... electric potential and electric potential energy is the same, right?
Almost! Electric potential is the amount of potential energy per unit of charge. So extremely related just not identical.
QED. LOL. Easter egg.
it possible to measure potential at zero current? Justify
An ideal volt-meter would do exactly that. Not the brand name Ideal, but ideal as in perfect. In the limit of a perfect design, a volt-meter would measure voltage without drawing any current, and will have infinite internal impedance.
Any REAL Voltmeter will always have a finite internal impedance (perhaps Gigaohms), and will draw a corresponding current to any voltage it measures (perhaps microamps).
Try this experiment. Construct a voltage divider with two 1 kOhm resistors, and measure the voltage between them. Surprise, surprise, it will be half the source voltage, just as you expect. Now try the same experiment with 1 Megaohm resistors instead. If your voltmeter also has an internal impedance that is comparable to 1 megaohm, you will measure a voltage that is noticeably less than half the source voltage. If that doesn't produce noticeable differences, try it with 10 Megaohm or 100 Megaohm resistors. Likely, the 100 Megaohm resistors forming a voltage divider, will divide the voltage to a lot less than half the source voltage, and show evidence of the Voltmeter's internal impedance.
Potential energy🤯😶🌫️😶🌫️
Flow of positive charge??!!!!!!!!!!!!!
yes, like a stream of protons
Im getting a tattoo with your name.
stop moving your arms
He's Italian. It's a reflex for him. Gestures are part of the way you communicate the Italian language, and it carries over when he speaks English as well.
@@carultch i forgot about this so ifk
@@carultch ok i remember i had to watch this for science
Thank you