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Britain & the wider world: 1745 -1901
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Rash Abdul
02/12/2025
Physics
Capacitors
56
•
2 Dec 2025
•
Rash Abdul
@jakey_ndfn
Capacitors are essential electronic components that store electrical energy in... Show more
A capacitor stores electrical energy in an electric field between two conductive plates. These plates are separated by a non-conductive material called a dielectric. This simple structure allows capacitors to perform various crucial functions in electronic circuits.
When voltage is applied to a capacitor, an electric field forms between the plates. This field stores energy as electrostatic potential energy - think of it like stretching a spring that wants to return to its original position. The amount of charge a capacitor can store is directly proportional to both the applied voltage and the capacitance.
Quick Fact: Capacitors are one of the most common components in electronics - your smartphone contains hundreds of them!
Capacitance measures a capacitor's ability to store charge and is measured in Farads (F). The capacitance depends on the plates' size and shape, the distance between them, and the dielectric material used. Most practical capacitors use microfarads (μF) or picofarads (pF) since one Farad is quite large.
Capacitors come in several varieties, each suited for different applications:
Different capacitor types trade off properties like size, cost, stability, and maximum voltage rating. Choosing the right type is crucial for proper circuit operation.
Capacitors are incredibly versatile components used across countless applications. They excel at filtering out unwanted frequencies from signals, helping to clean up audio or radio transmissions. In power supplies, they smooth out voltage fluctuations, ensuring your devices receive stable power.
Energy storage is another key function - capacitors can rapidly discharge stored energy, which is perfect for camera flashes or emergency backup systems. They're also brilliant for timing circuits, creating precise delays in everything from traffic lights to microwave ovens.
Capacitors also serve as coupling devices, allowing AC signals to pass between different parts of a circuit while blocking DC components. This ability makes them crucial for audio equipment, radio receivers, and signal processing circuits.
Remember: Unlike batteries that store energy chemically, capacitors store energy in an electric field, allowing for much faster charging and discharging!
The relationship between charge, voltage, and capacitance is defined by the formula C = Q/V, where C is capacitance, Q is charge, and V is voltage. When you need to calculate the energy stored in a capacitor, use E = ½CV².
The time constant of a capacitor-resistor circuit is given by τ = RC. This tells you how quickly a capacitor charges or discharges through a resistor - a crucial concept for timing circuits. After one time constant, a capacitor charges to about 63% of the full voltage.
When working with capacitors, always check the voltage rating - exceeding this can damage or destroy the component. Also consider the operating temperature range, as capacitors can behave differently at extreme temperatures. Finally, be aware that real capacitors have some leakage current where charge slowly drains away, which can affect long-term circuit performance.
Our AI Companion is a student-focused AI tool that offers more than just answers. Built on millions of Knowunity resources, it provides relevant information, personalised study plans, quizzes, and content directly in the chat, adapting to your individual learning journey.
You can download the app from Google Play Store and Apple App Store.
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
Quotes from every main character
English LiteratureApp 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
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
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
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
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 apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
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
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
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
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
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 apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
Rash Abdul
@jakey_ndfn
Capacitors are essential electronic components that store electrical energy in an electric field. They consist of two conductive plates separated by a dielectric material, and they're fundamental building blocks in countless electronic circuits you encounter daily.
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A capacitor stores electrical energy in an electric field between two conductive plates. These plates are separated by a non-conductive material called a dielectric. This simple structure allows capacitors to perform various crucial functions in electronic circuits.
When voltage is applied to a capacitor, an electric field forms between the plates. This field stores energy as electrostatic potential energy - think of it like stretching a spring that wants to return to its original position. The amount of charge a capacitor can store is directly proportional to both the applied voltage and the capacitance.
Quick Fact: Capacitors are one of the most common components in electronics - your smartphone contains hundreds of them!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Capacitance measures a capacitor's ability to store charge and is measured in Farads (F). The capacitance depends on the plates' size and shape, the distance between them, and the dielectric material used. Most practical capacitors use microfarads (μF) or picofarads (pF) since one Farad is quite large.
Capacitors come in several varieties, each suited for different applications:
Different capacitor types trade off properties like size, cost, stability, and maximum voltage rating. Choosing the right type is crucial for proper circuit operation.
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Capacitors are incredibly versatile components used across countless applications. They excel at filtering out unwanted frequencies from signals, helping to clean up audio or radio transmissions. In power supplies, they smooth out voltage fluctuations, ensuring your devices receive stable power.
Energy storage is another key function - capacitors can rapidly discharge stored energy, which is perfect for camera flashes or emergency backup systems. They're also brilliant for timing circuits, creating precise delays in everything from traffic lights to microwave ovens.
Capacitors also serve as coupling devices, allowing AC signals to pass between different parts of a circuit while blocking DC components. This ability makes them crucial for audio equipment, radio receivers, and signal processing circuits.
Remember: Unlike batteries that store energy chemically, capacitors store energy in an electric field, allowing for much faster charging and discharging!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
The relationship between charge, voltage, and capacitance is defined by the formula C = Q/V, where C is capacitance, Q is charge, and V is voltage. When you need to calculate the energy stored in a capacitor, use E = ½CV².
The time constant of a capacitor-resistor circuit is given by τ = RC. This tells you how quickly a capacitor charges or discharges through a resistor - a crucial concept for timing circuits. After one time constant, a capacitor charges to about 63% of the full voltage.
When working with capacitors, always check the voltage rating - exceeding this can damage or destroy the component. Also consider the operating temperature range, as capacitors can behave differently at extreme temperatures. Finally, be aware that real capacitors have some leakage current where charge slowly drains away, which can affect long-term circuit performance.
Our AI Companion is a student-focused AI tool that offers more than just answers. Built on millions of Knowunity resources, it provides relevant information, personalised study plans, quizzes, and content directly in the chat, adapting to your individual learning journey.
You can download the app from Google Play Store and 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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Quotes from every main character
English LiteratureApp 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
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
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
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
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 apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
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
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
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
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
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 apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
Physics
Sociology