Internal Resistance of a Battery, EMF, Cell Terminal Voltage, Physics Problems

This physics video tutorial explains how to calculate the internal resistance of a battery when connected to a load resistor. It explains the difference between the terminal voltage across the resistor and the emf or electromotive force generated by the cell. This video contains examples and practice problem showing how to calculate the terminal voltage and the battery and the internal resistance of the cell. The terminal voltage of a battery decreases when electric current is drawn from the cell. As the current delivered by the battery increases, the terminal voltage decreases.
Electric Current In Circuits:
• Electric Current & Cir...
The Electric Battery:
• The Electric Battery a...
Ohm's Law Problems:
• Ohm's Law Explained - ...
Resistance and Resistivity:
• Resistivity and Resist...
Resistor Color Code:
• Resistor Color Code Ch...
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Electromotive Force of a Battery:
• Electromotive Force of...
Drift Velocity and Current Density:
• Drift Velocity, Curren...
Potential Difference Between Two Points:
• Potential Difference B...
Alternating Current Vs Direct Current:
• Alternating Current vs...
______________________________
Schematic Diagrams & Symbols:
• Schematic Diagrams & S...
Open, Closed, and Short Circuits:
• Open Circuits, Closed ...
Resistors In Series:
• Resistors In Series - ...
Resistors In Parallel:
• Resistors In Parallel ...
Physics PDF Worksheets:
www.video-tutor.net/physics-b...

[@TheOrganicChemistryTutor]

Final Exams and Video Playlists: www.video-tutor.net/

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[@TheOrganicChemistryTutor]

Thanks

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[@Arkalaky2]

You are killin it with this videos. Do you have plans to start magnetic fields anytime soon?

[@vibacourtney-battista6918]

excellent video on this topic, this was the only part of AS physics i was wobbly on before tomorrows exam

[@kyliek.9481]

I fucked up my first paper 😭🔫

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[@sahitiputcha]

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Eventhough I dont take any physic class , but I'm gonna save these video so I can learn it myself this summer time

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2021 and yes

[@stevec9669]

Best explanation on this subject on KZbin. Thanks much.

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This video cleared up a lot of things, thank you so much

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My final first year exam in about three hours... Wish me luck

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Such good video. Although it is not very logic, it is great for me to review.

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my physics exam tmr :p

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V. clear explanation and logical working. Thank you

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Very good explanation .

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[@SquatSimp]

This helped a ton- thanks man

[@celwinpaulapas1518]

Waw clean explaination. Thanks

[@ram_pande8039]

Explained well

[@anupamapatham1141]

Thanks a bunch🤩

[@sakariasakaria6364]

you great keep it up!

[@shadowkokufu9178]

Hi, will you do a video on a VI graph and calculating the internal resistance + current + emf by using the graph please?

[@peteralkhabout8920]

how we can calculate it from the graph though ?

[@matomekgorane8880]

Excellent explanation ...I really enjoyed your lesson 🤩🤩 am just looking forward for more lessons ☺️☺️

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I can't speak english but, These lessons are so good.

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Gud explanation

[@user-lk4dg8on6c]

I really enjoy your subject only when you add more questions to it

[@wilburanderson4565]

Thanks boss

[@francisseun]

Thank you God bless you

[@oyeludejomiloju704]

Thank you 🥺

[@dilaraflor4191]

At 3:10 you used the total resistance to solve for the current but at 8:42 you solved for the current by only using the R of the load resistor should it not be the total (r + R) when solving for the current ?

[@masaemwas5919]

Yeah that part confused me too

[@ranganathd5954]

you are a very good teacher thanks a lot sir

[@carlytran711]

wow thank you

[@jillaloo5152]

How to find internal resistance given voltage, current and resistance? Electromotive force is not given

[@Obenai-j4t]

I am watching this video in my exam 😊 .

[@katushadeeva6909]

life saver

[@zarrinrazaq3339]

Usefull demo. What software are you using here?

[@TheOrganicChemistryTutor]

I talk about in this video: kzbin.info/www/bejne/qHO2poClpLKMqNU

[@karanaage3946]

🙏 thanks

[@drpriya23]

Why during charging V= e.m.f + Ir??

[@kalindakamwale3929]

I have a question it actually comes from the text book titled "success in electronics" 2nd edition In Unit 2 Direct Current subtitle 2.14 problems. No 14 the last problem. It has fig 2.20, and the question says in fig 2.20, V is a high resistance voltmeter. a) it reads 6V when the switch is open and 4.8V when it is closed. Calculate the e.m.f and internal resistance of the battery battery. Please help.

[@kalindakamwale3929]

The book is by Tom Duncan. Reprinted 2013.

[@hibyelol4727]

Is total resistance same as effective resistance?

[@adrianmok8557]

I have a question: if I were to find the internal resistance of a battery, should I use a resistor with higher resistance or one with a lower resistance? Thank you.

[@msmventures799]

Did you find the answer yet?

[@icemoodmage]

Hands down.

[@IvanPavlov007]

Thanks! And what if it's an old battery? What happens to the e.m.f. and the internal resistance as the battery ages and loses its charge?

[@ziadsydek]

First the e.m.f is what is written on battery's by company's and nothing happens to it but The terminal potential is the actual value of the battery and as time gose it decrease bec of internal resistance of the battery and this is called lost potential Then emf= t.p + l.p

[@riyajadhav1911]

thank uuu soo mucchh👍👍

[@NMPVevoOfficial]

What do we do if they didnt give us the internal resistence? Thanks tho

[@dhyangundu9635]

I like how that guy uses a calc for multiplying 0.11988 and 100

[@frogj0]

how to find emf when no current flows?

[@paulna5526]

finally somebody that knows what they're talking about, excellent job, i can't believe the other ah's on youtube that are providing so much misinfo., it is ridiculous.

[@hammadsaeed877]

On which app you teach us tell me plz?

[@satarupadebsinha3413]

Nicely explained

[@sn4rdnsn]

yea a magnetic fields video would be great

[@amazonabera2918]

sir i love ur videos they helped me alot .sir if u have avideo which shows potential difference between two points in the circuit

[@TheOrganicChemistryTutor]

Here it is: kzbin.info/www/bejne/g5_Te6KZg6dpo8U

[@lineekelaleonard4808]

2. Terminal pd across the battery is measured at 6.2 V. The battery consists of 2 cells connected in parallel. Given that R_total is 3.1Ω and A measures 2 A: 2.1 Determine the emf of the battery. How can I solve this JG?🤔

[@Xxxcappie23]

Great vid .At the time 3:35 Why do we not multiply by 101 ohms being the total resistance?? Instead you multiplied by the 100 ohms resistor . I may have complicated this by asking plz explain...

[@aleena158]

If I understand your question right, the R=1ohm R=100 ohm Is more like part (i) part (ii) The question can be taken as find internal resistance when external resistance is (a) 1ohm (b) 100 ohm

[@geirha75]

Does it really work in "real life"? I mean calculating internal battery resistance 12V car battery the way done in the video?

[@Kryto]

Can you do the same, but a little more practical? In this situation you wanted to calculate and measure internal resistance, and you had the Emf value. But in a real situation you cant relay on the value you get from the producers. Since most batteries wear out with use (at the same time internal resistance increases) In other words. Calculate Internal resistance with Emf as an unknown value.

[@benjaminbissick2539]

Agree

[@benjaminbissick2539]

Agree ......please to do so

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[@SkystormX05]

tysm

[@onyeagoluhenry60]

A circuit consists of a variable resistor R connected in series with an ammeter and a cell. A voltmeter is connected in parallel across the variable resistor R. the cell is of e.m.f E and internal resistance r. For a certain value of R, the voltmeter reads 4V and the ammeter reads 1A. When R is adjusted, the voltmeter reads 2V and the ammeter reads 2.5A. Draw the circuit diagram and calculate the values of E and r. Please help!!

[@buddhabhushanchakre1767]

Two resistor 12 ohm and 6 ohm are connected in parallel and this combination connected in series with 6.25 ohm and battery has internal resistance of 0.25 ohm how to find emf of battery???

[@itstheannas]

Do you not have the current given? Or the total power dissipated? If so, is it an expression you have to fond or a value?

[@epicbaconugget704]

you can also calculate internal resistance without finding current just by doing (1 - 11.9/12) x 50

[@Todaywalnut]

What's the principle you're using?

[@colamentos4738]

EP1C (ocn) where did you find that? :\

[@sultansultan5447]

For your last equation you divided by -12 and your overall result was .42 however to my understanding another way I tried which goes by the rules of transposition if you have 11.9=12-0.238r if you move the r to the other side of the = side and the same with the 11.9 makes it -r=12-0.238-11.9 then change all the signs of positive to negative to both sides making it r=-12+0.238+11.9 and get result of 0.138. either I'm wrong or you are. If there is anyone here who understands this better then me please explain. Thanks

[@blacklyrics049]

dayum, 11.9 = 12 - 0.238r ; here 'r' is multiplied to -0.238, so you can't just simply take only the 'r' to the other side of the equation, you gotta take the whole -0.238r to the left, if you want to, and the equation will be 11.9 + 0.238r = 12, then you can carry out this...

[@idk-dr7fo]

tysm i got it 4jan2022 7:28 pm

[@rookiemvp2008]

My brain is exploding trying to understand this stuff

[@diana0423]

Thanks a lot!!!!!

[@imaneggagrass5573]

how do i calculate terminal voltage when internal resistance (r) is unknown? :"(

[@sultansultan5447]

Get your voltage difference between your load. With that voltage find the current using ohm's law assuming you know the resistance of the circuit. After you have the current of the circuit and the voltage difference use equation: vr( the voltage difference you measured) = ( the internal resistance of the battery which you don't know)- Current multiplied by the resistance. You simply get vr to the other side of the = sign to become a -vr and the internal resistance to the other side so the equation would be your internal resistance= - vr - ir. Vr is voltage difference and ir is current multiply by resistance that would give internal voltage.

[@brayton6683]

I'm writing a test tomorrow ☠☠☠🤧 it's on circuits and electrostatic

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or for last r=e-v/I same thing just easier for me to solve straight away if remember this

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Final touches 😊 exams at 2

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🙏🏼

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my exam is in 12 hours and im 12 weeks behind 💀

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Exams in 30 min😭

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[@UltraTheBeastt]

what are you saying ???

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He is proposing to include Arabic captions for the video

[@zeusong149]

isn't that parallel?

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exams in an hour

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Anyone studying this in 10th grade?

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Me

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Use the question I gave you plz

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im so fucked

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There isn't anything that you don't know.

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Why your voice make me sleep🙄🙄🙄

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Thanks for wasting 19 mins of my time for knowing nothing.

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???

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U mean 10 mins

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I didn't liked this teaching... Sorrry