11.3. Capacitance
Capacitors are electrical components used in almost all electronic devices around us. They are really useful for a number of reasons, including timing, smoothing and rectification. They are remarkably simple in their structure - two conductive parallel plates separated by an insulator. The main function of a capacitor is to store electrical charge, one plate being positive and one plate being negative. We are going to explore a bit into the structure of these things, as well as how they can be useful in circuits.
Before we do, I'd like to introduce you to 'ElectroBoom', aka Mehdi Sadaghdar - a YouTuber who puts up lots of great electricity videos, most of which involve him shocking himself in various elaborate ways. Here he looks at these capacitor things.
I have divided this subsection into the following bits:
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Capacitors and Capacitance - introducing some key terms, equations and definitions
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Dielectrics - looking closer at the structure of these things
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Combining Capacitors - the rules if we have capacitors in parallel or series
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Charging/ Discharging Capacitors - going back to our exponential decay ideas (
Capactors and Capacitance
So, how exactly do these capacitors work?
Video Lessons
Chris Doner | Capacitance | IB Specific | ||||
Khan Academy | Capacitors and Capacitance | Capacitance | Energy of a Capacitor | |||
Science Shorts | Capacitors | Practical Tips |
Resources
IB Physics | Topic 11 Notes | |||||
IB-Physics.net | Chapter 11 Summary | IB Revision Notes | ||||
Isaac Physics | Capacitance | |||||
Mr. G | 11.3 Teaching Notes | 11.3 Student Notes | ||||
Physics and Maths Tutor | Fields Definitions | Fields Key Points | Fields Detailed Notes | Capacitance Flashcards | A Level Resources - content slightly different |
Questions
Dielectrics
Video Lessons
Chris Doner | Capacitance (Dielectrics) | IB Specific | ||||
Khan Academy | Dielectrics in Capacitors |
Resources
IB Physics | Topic 11 Notes | |||||
IB-Physics.net | Chapter 11 Summary | IB Revision Notes | ||||
Isaac Physics | Capacitance | |||||
Mr. G | 11.3 Teaching Notes | 11.3 Student Notes | ||||
Physics and Maths Tutor | Fields Definitions | Fields Key Points | Fields Detailed Notes | Capacitance Flashcards | A Level Resources - content slightly different |
Questions
Cambridge University Press | Topic 11: MCQs | CUP Website Link | Freely available online | |||
Grade Gorilla | 11.3 (Capacitance) MCQs | Topic 11 (Induction) Final Quiz | Quick IB Specific Mixed MCQs | |||
Mr. G | 11.3 Formative Assessment | Topic 11 Summary Qs | IB Specific Questions |
Combining Capacitors
Video Lessons
Chris Doner | Capacitance (Combining Capacitors) | IB Specific | ||||
Khan Academy | Capacitors in Series | Capacitors in Parallel |
Resources
IB Physics | Topic 11 Notes | |||||
IB-Physics.net | Chapter 11 Summary | IB Revision Notes | ||||
Isaac Physics | Series and Parallel | |||||
Mr. G | 11.3 Teaching Notes | 11.3 Student Notes | ||||
Physics and Maths Tutor | Fields Definitions | Fields Key Points | Fields Detailed Notes | Capacitance Flashcards | A Level Resources - content slightly different |
Questions
Cambridge University Press | Topic 11: MCQs | CUP Website Link | Freely available online | |||
Grade Gorilla | 11.3 (Capacitance) MCQs | Topic 11 (Induction) Final Quiz | Quick IB Specific Mixed MCQs | |||
Isaac Physics | Capacitor Networks | |||||
Mr. G | 11.3 Formative Assessment | Topic 11 Summary Qs | IB Specific Questions |
Charging/ Discharging Capacitor Circuits
When releasing their charge through a circuit, capacitors follow an exponential decay.
Video Lessons
Chris Doner | Charging and Discharging | IB Specific | ||||
Science Shorts | Capacitor Discharge | Practical Tips |
Resources
IB Physics | Topic 11 Notes | |||||
IB-Physics.net | Chapter 11 Summary | IB Revision Notes | ||||
Isaac Physics | Exponentials Maths Recap | Charging and Discharging | ||||
Isaac Physics | Charging and Discharging | |||||
Mr. G | 11.3 Teaching Notes | 11.3 Student Notes | ||||
Physics and Maths Tutor | Fields Definitions | Fields Key Points | Fields Detailed Notes | Capacitance Flashcards | A Level Resources - content slightly different |
Questions
Cambridge University Press | Topic 11: MCQs | CUP Website Link | Freely available online | |||
Grade Gorilla | 11.3 (Capacitance) MCQs | Topic 11 (Induction) Final Quiz | Quick IB Specific Mixed MCQs | |||
Isaac Physics | Discharge of a Capacitor | |||||
Mr. G | 11.3 Formative Assessment | Topic 11 Summary Qs | IB Specific Questions | |||
Physics and Maths Tutor | Charging & Discharging (AQA 2) | Charging & Discharging MS (AQA 2) | A-Level Qs: overlapping content |
Additional Resources
IB Questions
A question by question breakdown of the IB papers by year is shown below to allow you to filter questions by topic. Hopefully you have access to many of these papers through your school system. If available, there may be some links to online sources of questions, though please be patient if the links are broken! (DrR: If you do find some broken links, please contact me through the site)
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Questions on this topic (Section 11) are shown in green.
Use this grid to practice past IB questions topic by topic. You can see from the colours how similar the question topic breakdown is year by year. The more you can familiarise yourself with the IB question style the better - eventually you will come to spot those tricks and types of questions that reappear each year.