Biology
Chemistry
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Amy Wan
11/29/2025
Physics
Physics
60
•
Nov 29, 2025
•
Amy Wan
@amymel0n
Electric circuits might seem complex, but they're actually quite straightforward... Show more
Understanding circuit symbols is like learning the alphabet of electronics - once you know them, you can read any circuit diagram. The most essential components include cells (which push electrons around circuits) and batteries (multiple cells working together).
Resistors are crucial for controlling current flow. Fixed resistors limit current by a set amount, while variable resistors let you adjust the current - think of a dimmer switch for lights. Some resistors even respond to their environment: light dependent resistors (LDRs) change resistance based on brightness, and thermistors change with temperature.
Safety components like fuses protect circuits by melting if too much current flows through. Meanwhile, measuring devices like ammeters (for current) and voltmeters (for potential difference) help you understand what's happening in your circuit.
Quick Tip: Remember that LEDs and regular bulbs both emit light, but LEDs are much more efficient and last longer!
Electric current flows like a river of electrons carrying energy around a circuit, measured in amperes (A). The key rule to remember: current is never "used up" - it's the same all the way around a series circuit.
In a series circuit, there's only one path for current to take. This means if one component breaks, the whole circuit stops working (like old Christmas lights). The current has the same value everywhere in the loop.
Parallel circuits work differently - they have multiple branches for current to flow through. The total current splits up between the branches, then rejoins before returning to the cell. If you measure 0.3A leaving the cell, and one branch carries 0.1A while another carries 0.2A, they add up perfectly .
Remember: In series circuits, current stays constant. In parallel circuits, current divides between branches but the total always adds up!
Potential difference (or voltage) is the electrical "push" that drives current through components - think of it as electrical pressure. In series circuits, this voltage gets shared between all components, like splitting a pizza between friends.
When you connect identical bulbs in series, each gets an equal share of the total potential difference. This is why bulbs in series are dimmer than when connected alone - they're each getting less voltage to work with.
Parallel circuits behave completely differently. Here, each branch gets the full voltage from the cell, which is why bulbs in parallel shine brighter than those in series. The potential difference across each parallel branch equals the cell's total voltage.
Key Point: Series circuits share voltage between components, while parallel circuits give full voltage to each branch - that's why your house uses parallel wiring!
Resistance determines how much a component opposes the flow of current, measured in ohms (Ω). Think of it like a narrow pipe restricting water flow - higher resistance means less current can pass through.
The relationship between voltage, current, and resistance follows Ohm's Law: Resistance = Voltage ÷ Current . This equation is your best friend for circuit calculations and will appear constantly in your exams.
For fixed resistors, the resistance stays constant as long as temperature doesn't change. This creates a straight line on a current-voltage graph, showing that current increases proportionally with voltage.
Exam Tip: Master the resistance equation R = V/I - you'll use it in almost every circuit calculation question!
Filament lamps break the rules you've just learned about resistors, and that's what makes them interesting! Unlike fixed resistors, their resistance changes as they heat up.
When you increase the potential difference across a filament bulb, it gets hotter and brighter. However, this heat causes the resistance to increase, which means less current flows than you'd expect from Ohm's Law.
The reason is simple: as the filament heats up, electrons collide more frequently with the hot metal atoms. These extra collisions make it harder for current to flow, effectively increasing the resistance. This is why a filament lamp's current-voltage graph curves rather than forming a straight line.
Physics Insight: This heating effect is actually useful - it's how the bulb produces light, converting electrical energy into heat and light energy!
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.
You can download the app in the Google Play Store and in the Apple App Store.
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
App Store
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 THE SCHOOLGPT. 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 THE SCHOOLGPT. 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
Amy Wan
@amymel0n
Electric circuits might seem complex, but they're actually quite straightforward once you understand the basic components and how current behaves. Think of electricity like water flowing through pipes - it needs a complete path to flow and different components affect... Show more
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Understanding circuit symbols is like learning the alphabet of electronics - once you know them, you can read any circuit diagram. The most essential components include cells (which push electrons around circuits) and batteries (multiple cells working together).
Resistors are crucial for controlling current flow. Fixed resistors limit current by a set amount, while variable resistors let you adjust the current - think of a dimmer switch for lights. Some resistors even respond to their environment: light dependent resistors (LDRs) change resistance based on brightness, and thermistors change with temperature.
Safety components like fuses protect circuits by melting if too much current flows through. Meanwhile, measuring devices like ammeters (for current) and voltmeters (for potential difference) help you understand what's happening in your circuit.
Quick Tip: Remember that LEDs and regular bulbs both emit light, but LEDs are much more efficient and last longer!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Electric current flows like a river of electrons carrying energy around a circuit, measured in amperes (A). The key rule to remember: current is never "used up" - it's the same all the way around a series circuit.
In a series circuit, there's only one path for current to take. This means if one component breaks, the whole circuit stops working (like old Christmas lights). The current has the same value everywhere in the loop.
Parallel circuits work differently - they have multiple branches for current to flow through. The total current splits up between the branches, then rejoins before returning to the cell. If you measure 0.3A leaving the cell, and one branch carries 0.1A while another carries 0.2A, they add up perfectly .
Remember: In series circuits, current stays constant. In parallel circuits, current divides between branches but the total always adds up!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Potential difference (or voltage) is the electrical "push" that drives current through components - think of it as electrical pressure. In series circuits, this voltage gets shared between all components, like splitting a pizza between friends.
When you connect identical bulbs in series, each gets an equal share of the total potential difference. This is why bulbs in series are dimmer than when connected alone - they're each getting less voltage to work with.
Parallel circuits behave completely differently. Here, each branch gets the full voltage from the cell, which is why bulbs in parallel shine brighter than those in series. The potential difference across each parallel branch equals the cell's total voltage.
Key Point: Series circuits share voltage between components, while parallel circuits give full voltage to each branch - that's why your house uses parallel wiring!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Resistance determines how much a component opposes the flow of current, measured in ohms (Ω). Think of it like a narrow pipe restricting water flow - higher resistance means less current can pass through.
The relationship between voltage, current, and resistance follows Ohm's Law: Resistance = Voltage ÷ Current . This equation is your best friend for circuit calculations and will appear constantly in your exams.
For fixed resistors, the resistance stays constant as long as temperature doesn't change. This creates a straight line on a current-voltage graph, showing that current increases proportionally with voltage.
Exam Tip: Master the resistance equation R = V/I - you'll use it in almost every circuit calculation question!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Filament lamps break the rules you've just learned about resistors, and that's what makes them interesting! Unlike fixed resistors, their resistance changes as they heat up.
When you increase the potential difference across a filament bulb, it gets hotter and brighter. However, this heat causes the resistance to increase, which means less current flows than you'd expect from Ohm's Law.
The reason is simple: as the filament heats up, electrons collide more frequently with the hot metal atoms. These extra collisions make it harder for current to flow, effectively increasing the resistance. This is why a filament lamp's current-voltage graph curves rather than forming a straight line.
Physics Insight: This heating effect is actually useful - it's how the bulb produces light, converting electrical energy into heat and light energy!
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.
You can download the app in the Google Play Store and in the Apple App Store.
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
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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 THE SCHOOLGPT. 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 THE SCHOOLGPT. 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
