Elektrina je všade okolo nás - v telefónoch, počítačoch, svetlách.... Show more
Fyzika
Slovenský jazyk
Angličtina
MatematikaSign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
19
•
Updated Mar 22, 2026
•
Základy Elektrického Prúdu a Ohmovho Zákona
1 / 8
Elektrický prúd a Ohmov zákon - Základy
Elektrický prúd je ako prúd vody v rieke, len namiesto vody sa pohybujú elektróny vo vodičoch. Merá sa v Ampéroch (A) pomocou ampérmetra.
Elektrické napätie funguje ako tlak vody v potrubí - tlačí elektróny, aby sa pohybovali. Jednotka je Volt (V) a merá sa voltmetrom.
Elektrický odpor je ako zúžené potrubie, ktoré bráni toku. Čím väčší odpor, tým ťažšie sa elektróny pohybujú. Jednotka je Ohm (Ω).
💡 Tip: Predstav si elektrický obvod ako vodovodný systém - napätie je tlak, prúd je prietok a odpor sú prekážky v potrubí!
Elektrický prúd podrobnejšie
Prúd vzniká, keď sa vo vodiči začnú elektróny pohybovať usporiadane. Konvenčný smer prúdu ide od + k - pólu, ale skutočné elektróny sa pohybujú opačne.
Výpočet prúdu: I = Q/t, kde Q je náboj v coulomboch a t je čas v sekundách. Toto ti pomôže pochopiť, koľko elektrónov prejde vodičom za určitý čas.
Ampérmeter sa vždy zapája do série (za sebou) s meranou časťou obvodu - musí ním pretekať rovnaký prúd ako meranou súčiastkou.
⚠️ Pozor: Nikdy nezabudni na správne zapojenie ampérmetra - inak ho môžeš poškodiť!
Elektrické napätie a odpor
Napätie je energia, ktorá "tlačí" elektróny po obvode. Vzorec: U = W/Q, kde W je energia a Q je náboj. Voltmeter sa zapája paralelne k meranej súčiastke.
Odpor závisí od štyroch faktorov: dĺžky vodiča , plochy prierezu , materiálu a teploty.
Vzorec pre odpor: R = ρ × l/S, kde ρ (ró) je rezistivita materiálu, l je dĺžka a S je plocha prierezu.
🔍 Zaujímavosť: Meď má nízku rezistivitu (dobrý vodič), zatiaľ čo guma má vysokú (izolant).
Ohmov zákon - Kľúčový vzťah
Ohmov zákon je základný vzťah elektrotechniky: U = R × I. Napätie je priamo úmerné prúdu a odporu.
Z tohto vzorca môžeš odvodiť: I = U/R (výpočet prúdu) a R = U/I (výpočet odporu). Tento zákon platí pre väčšinu bežných súčiastok.
Pri riešení úloh si vždy najprv zapíš dané hodnoty, zvoľ správny vzorec a skontroluj jednotky. Všetko musí byť v základných jednotkách (V, A, Ω).
📝 Pamätaj: Ohmov zákon je tvoj najlepší kamarát pri riešení úloh z elektrotechniky!
Praktické príklady
Príklad 1: Žiarovka má odpor 240 Ω pri napätí 230 V. Prúd: I = U/R = 230/240 ≈ 0,96 A.
Príklad 2: Varič s prúdom 8 A pri 230 V má odpor: R = U/I = 230/8 = 28,75 Ω.
Príklad 3: LED s odporom 150 Ω a prúdom 20 mA potrebuje napätie: U = R × I = 150 × 0,02 = 3 V.
⚡ Kľúč k úspechu: Vždy preveď jednotky (mA na A, kV na V) a skontroluj si výsledok!
Praktické tipy a bezpečnosť
Jednotky sú kľúčové! Vždy skontroluj, či máš všetky veličiny v základných jednotkách. Ampérmeter zapájaj do série, voltmeter paralelne.
Ohmov zákon platí len pre ohmické odpory. Niektoré súčiastky ako diódy majú premenlivý odpor.
S elektrinou buď vždy opatrný! Vysoké napätie a prúd môžu byť nebezpečné - nikdy nepracuj bez dozoru dospelého.
🛡️ Bezpečnosť: Pri práci s elektrinou platí - radšej sa spýtaj dvakrát než riskovať úraz!
Rýchly súhrn na záver
Základné vzorce: I = Q/t (prúd), U = W/Q (napätie), R = ρl/S (odpor), U = R × I (Ohmov zákon).
Jednotky: Ampér (A) pre prúd, Volt (V) pre napätie, Ohm (Ω) pre odpor. Zapojenie: Ampérmeter do série, voltmeter paralelne.
Toto sú základy, ktoré potrebuješ vedieť na testy. S týmito vzorcami a správnym pochopením zvládneš každú úlohu z elektrotechniky!
🎯 Záver: Elektrotechnika nie je zložitá - stačí pochopiť základy a pravidelne cvičiť!
We thought you’d never ask...
What is the Knowunity AI companion?
Our AI companion is specifically built for the needs of students. Based on the millions of content pieces we have on the platform we can provide truly meaningful and relevant answers to students. But its not only about answers, the companion is even more about guiding students through their daily learning challenges, with personalised study plans, quizzes or content pieces in the chat and 100% personalisation based on the students skills and developments.
Where can I download the Knowunity app?
You can download the app in the Google Play Store and in the Apple App Store.
Is Knowunity really free of charge?
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
Most popular content in Fyzika
Most popular content
Can't find what you're looking for? Explore other subjects.
Students love us — and so will you.
4.6/5
App Store
4.7/5
Google Play
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
I think it’s very much worth it and you’ll end up using it a lot once you get the hang of it and even after looking at others notes you can still ask your Artificial intelligence buddy the question and ask to simplify it if you still don’t get it!!! In the end I think it’s worth it 😊👍 ⚠️Also DID I MENTION ITS FREEE YOU DON’T HAVE TO PAY FOR ANYTHING AND STILL GET YOUR GRADES IN PERFECTLY❗️❗️⚠️
Thomas R
iOS user
Knowunity is the BEST app I’ve used in a minute. This is not an ai review or anything this is genuinely coming from a 7th grade student (I know 2011 im young) but dude this app is a 10/10 i have maintained a 3.8 gpa and have plenty of time for gaming. I love it and my mom is just happy I got good grades
Brad T
Android user
Not only did it help me find the answer but it also showed me alternative ways to solve it. I was horrible in math and science but now I have an a in both subjects. Thanks for the help🤍🤍
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
I found this app a couple years ago and it has only gotten better since then. I really love it because it can help with written questions and photo questions. Also, it can find study guides that other people have made as well as flashcard sets and practice tests. The free version is also amazing for students who might not be able to afford it. Would 100% recommend
Aubrey
iOS user
Best app if you're in Highschool or Junior high. I have been using this app for 2 school years and it's the best, it's good if you don't have anyone to help you with school work.😋🩷🎀
Marco B
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE Knowunity AI. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This app is phenomenal down to the correct info and the various topics you can study! I greatly recommend it for people who struggle with procrastination and those who need homework help. It has been perfectly accurate for world 1 history as far as I’ve seen! Geometry too!
Paul T
iOS user
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
I think it’s very much worth it and you’ll end up using it a lot once you get the hang of it and even after looking at others notes you can still ask your Artificial intelligence buddy the question and ask to simplify it if you still don’t get it!!! In the end I think it’s worth it 😊👍 ⚠️Also DID I MENTION ITS FREEE YOU DON’T HAVE TO PAY FOR ANYTHING AND STILL GET YOUR GRADES IN PERFECTLY❗️❗️⚠️
Thomas R
iOS user
Knowunity is the BEST app I’ve used in a minute. This is not an ai review or anything this is genuinely coming from a 7th grade student (I know 2011 im young) but dude this app is a 10/10 i have maintained a 3.8 gpa and have plenty of time for gaming. I love it and my mom is just happy I got good grades
Brad T
Android user
Not only did it help me find the answer but it also showed me alternative ways to solve it. I was horrible in math and science but now I have an a in both subjects. Thanks for the help🤍🤍
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
I found this app a couple years ago and it has only gotten better since then. I really love it because it can help with written questions and photo questions. Also, it can find study guides that other people have made as well as flashcard sets and practice tests. The free version is also amazing for students who might not be able to afford it. Would 100% recommend
Aubrey
iOS user
Best app if you're in Highschool or Junior high. I have been using this app for 2 school years and it's the best, it's good if you don't have anyone to help you with school work.😋🩷🎀
Marco B
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE Knowunity AI. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This app is phenomenal down to the correct info and the various topics you can study! I greatly recommend it for people who struggle with procrastination and those who need homework help. It has been perfectly accurate for world 1 history as far as I’ve seen! Geometry too!
Paul T
iOS user
Základy Elektrického Prúdu a Ohmovho Zákona
Elektrina je všade okolo nás - v telefónoch, počítačoch, svetlách. Ak pochopíš základy elektrického prúdu a Ohmov zákon, budeš vedieť, ako fungujú mnohé veci v tvojom živote a prečo sú niektoré obvody bezpečné a iné nie.
Elektrický prúd a Ohmov zákon - Základy
Elektrický prúd je ako prúd vody v rieke, len namiesto vody sa pohybujú elektróny vo vodičoch. Merá sa v Ampéroch (A) pomocou ampérmetra.
Elektrické napätie funguje ako tlak vody v potrubí - tlačí elektróny, aby sa pohybovali. Jednotka je Volt (V) a merá sa voltmetrom.
Elektrický odpor je ako zúžené potrubie, ktoré bráni toku. Čím väčší odpor, tým ťažšie sa elektróny pohybujú. Jednotka je Ohm (Ω).
💡 Tip: Predstav si elektrický obvod ako vodovodný systém - napätie je tlak, prúd je prietok a odpor sú prekážky v potrubí!
Sign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
Elektrický prúd podrobnejšie
Prúd vzniká, keď sa vo vodiči začnú elektróny pohybovať usporiadane. Konvenčný smer prúdu ide od + k - pólu, ale skutočné elektróny sa pohybujú opačne.
Výpočet prúdu: I = Q/t, kde Q je náboj v coulomboch a t je čas v sekundách. Toto ti pomôže pochopiť, koľko elektrónov prejde vodičom za určitý čas.
Ampérmeter sa vždy zapája do série (za sebou) s meranou časťou obvodu - musí ním pretekať rovnaký prúd ako meranou súčiastkou.
⚠️ Pozor: Nikdy nezabudni na správne zapojenie ampérmetra - inak ho môžeš poškodiť!
Sign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
Elektrické napätie a odpor
Napätie je energia, ktorá "tlačí" elektróny po obvode. Vzorec: U = W/Q, kde W je energia a Q je náboj. Voltmeter sa zapája paralelne k meranej súčiastke.
Odpor závisí od štyroch faktorov: dĺžky vodiča , plochy prierezu , materiálu a teploty.
Vzorec pre odpor: R = ρ × l/S, kde ρ (ró) je rezistivita materiálu, l je dĺžka a S je plocha prierezu.
🔍 Zaujímavosť: Meď má nízku rezistivitu (dobrý vodič), zatiaľ čo guma má vysokú (izolant).
Sign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
Ohmov zákon - Kľúčový vzťah
Ohmov zákon je základný vzťah elektrotechniky: U = R × I. Napätie je priamo úmerné prúdu a odporu.
Z tohto vzorca môžeš odvodiť: I = U/R (výpočet prúdu) a R = U/I (výpočet odporu). Tento zákon platí pre väčšinu bežných súčiastok.
Pri riešení úloh si vždy najprv zapíš dané hodnoty, zvoľ správny vzorec a skontroluj jednotky. Všetko musí byť v základných jednotkách (V, A, Ω).
📝 Pamätaj: Ohmov zákon je tvoj najlepší kamarát pri riešení úloh z elektrotechniky!
Sign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
Praktické príklady
Príklad 1: Žiarovka má odpor 240 Ω pri napätí 230 V. Prúd: I = U/R = 230/240 ≈ 0,96 A.
Príklad 2: Varič s prúdom 8 A pri 230 V má odpor: R = U/I = 230/8 = 28,75 Ω.
Príklad 3: LED s odporom 150 Ω a prúdom 20 mA potrebuje napätie: U = R × I = 150 × 0,02 = 3 V.
⚡ Kľúč k úspechu: Vždy preveď jednotky (mA na A, kV na V) a skontroluj si výsledok!
Sign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
Praktické tipy a bezpečnosť
Jednotky sú kľúčové! Vždy skontroluj, či máš všetky veličiny v základných jednotkách. Ampérmeter zapájaj do série, voltmeter paralelne.
Ohmov zákon platí len pre ohmické odpory. Niektoré súčiastky ako diódy majú premenlivý odpor.
S elektrinou buď vždy opatrný! Vysoké napätie a prúd môžu byť nebezpečné - nikdy nepracuj bez dozoru dospelého.
🛡️ Bezpečnosť: Pri práci s elektrinou platí - radšej sa spýtaj dvakrát než riskovať úraz!
Sign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
Rýchly súhrn na záver
Základné vzorce: I = Q/t (prúd), U = W/Q (napätie), R = ρl/S (odpor), U = R × I (Ohmov zákon).
Jednotky: Ampér (A) pre prúd, Volt (V) pre napätie, Ohm (Ω) pre odpor. Zapojenie: Ampérmeter do série, voltmeter paralelne.
Toto sú základy, ktoré potrebuješ vedieť na testy. S týmito vzorcami a správnym pochopením zvládneš každú úlohu z elektrotechniky!
🎯 Záver: Elektrotechnika nie je zložitá - stačí pochopiť základy a pravidelne cvičiť!
Sign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
We thought you’d never ask...
What is the Knowunity AI companion?
Our AI companion is specifically built for the needs of students. Based on the millions of content pieces we have on the platform we can provide truly meaningful and relevant answers to students. But its not only about answers, the companion is even more about guiding students through their daily learning challenges, with personalised study plans, quizzes or content pieces in the chat and 100% personalisation based on the students skills and developments.
Where can I download the Knowunity app?
You can download the app in the Google Play Store and in the Apple App Store.
Is Knowunity really free of charge?
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
0
Smart Tools NEW
Transform this note into: ✓ 50+ Practice Questions ✓ Interactive Flashcards ✓ Full Practice Test ✓ Essay Outlines
Practice Test
Quiz
Flashcards
Essay
Most popular content in Fyzika
Most popular content
Can't find what you're looking for? Explore other subjects.
Students love us — and so will you.
4.6/5
App Store
4.7/5
Google Play
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
I think it’s very much worth it and you’ll end up using it a lot once you get the hang of it and even after looking at others notes you can still ask your Artificial intelligence buddy the question and ask to simplify it if you still don’t get it!!! In the end I think it’s worth it 😊👍 ⚠️Also DID I MENTION ITS FREEE YOU DON’T HAVE TO PAY FOR ANYTHING AND STILL GET YOUR GRADES IN PERFECTLY❗️❗️⚠️
Thomas R
iOS user
Knowunity is the BEST app I’ve used in a minute. This is not an ai review or anything this is genuinely coming from a 7th grade student (I know 2011 im young) but dude this app is a 10/10 i have maintained a 3.8 gpa and have plenty of time for gaming. I love it and my mom is just happy I got good grades
Brad T
Android user
Not only did it help me find the answer but it also showed me alternative ways to solve it. I was horrible in math and science but now I have an a in both subjects. Thanks for the help🤍🤍
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
I found this app a couple years ago and it has only gotten better since then. I really love it because it can help with written questions and photo questions. Also, it can find study guides that other people have made as well as flashcard sets and practice tests. The free version is also amazing for students who might not be able to afford it. Would 100% recommend
Aubrey
iOS user
Best app if you're in Highschool or Junior high. I have been using this app for 2 school years and it's the best, it's good if you don't have anyone to help you with school work.😋🩷🎀
Marco B
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE Knowunity AI. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This app is phenomenal down to the correct info and the various topics you can study! I greatly recommend it for people who struggle with procrastination and those who need homework help. It has been perfectly accurate for world 1 history as far as I’ve seen! Geometry too!
Paul T
iOS user
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
I think it’s very much worth it and you’ll end up using it a lot once you get the hang of it and even after looking at others notes you can still ask your Artificial intelligence buddy the question and ask to simplify it if you still don’t get it!!! In the end I think it’s worth it 😊👍 ⚠️Also DID I MENTION ITS FREEE YOU DON’T HAVE TO PAY FOR ANYTHING AND STILL GET YOUR GRADES IN PERFECTLY❗️❗️⚠️
Thomas R
iOS user
Knowunity is the BEST app I’ve used in a minute. This is not an ai review or anything this is genuinely coming from a 7th grade student (I know 2011 im young) but dude this app is a 10/10 i have maintained a 3.8 gpa and have plenty of time for gaming. I love it and my mom is just happy I got good grades
Brad T
Android user
Not only did it help me find the answer but it also showed me alternative ways to solve it. I was horrible in math and science but now I have an a in both subjects. Thanks for the help🤍🤍
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
I found this app a couple years ago and it has only gotten better since then. I really love it because it can help with written questions and photo questions. Also, it can find study guides that other people have made as well as flashcard sets and practice tests. The free version is also amazing for students who might not be able to afford it. Would 100% recommend
Aubrey
iOS user
Best app if you're in Highschool or Junior high. I have been using this app for 2 school years and it's the best, it's good if you don't have anyone to help you with school work.😋🩷🎀
Marco B
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE Knowunity AI. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This app is phenomenal down to the correct info and the various topics you can study! I greatly recommend it for people who struggle with procrastination and those who need homework help. It has been perfectly accurate for world 1 history as far as I’ve seen! Geometry too!
Paul T
iOS user