11.1. Electromagnetic Induction (HL)
Here we look back at the topics of electricity and magnetism. Michael Faraday was a hugely influential figure who did a lot of important work around understanding electricity and its relationship with magnetism (essentially leading to the subsequent important work by James Clerk Maxwell). He lends his name to Faraday's Law - a law which describes how an EMF is induced from moving a conductor in a magnetic field. For a bit of historical context to the chapter, take a look at this video by SciShow.
The section has been divided up as follows:
Inducing an EMF - introducing how we can generate an EMF in a conductor
Flux and Flux Linkage - a few key bits of terminology we need to get to grips with
Faraday's Law - a very important equation described by Michael Faraday
Lenz's Law - where does the force opposing motion come from?
Inducing an EMF in a Conductor
We have previously looked a little bit at the motor effect - that is moving charges experiencing a force in a magnetic field. Here we look at what is sometimes called the 'dynamo effect'.
Video Lessons
Chris Doner | EM Induction | IB Specific | ||||
Khan Academy | Induced Current in a wire | Induced EMF in a rod | ||||
Science Shorts | EM Induction |
Resources
IB Physics | Topic 11 Notes | |||||
IB-Physics.net | Chapter 11 Summary | IB Revision Notes | ||||
Mr. G | 11.1 Teaching Notes | 11.1 Student Notes | ||||
Physics and Maths Tutor | Fields Definitions | Fields Key Points | Fields Detailed Notes | B Field Flashcards | A Level Resources - content slightly different |
Questions
Cambridge University Press | Topic 11: MCQs | CUP Website Link | Freely available online | |||
Grade Gorilla | 11.1 (Induction) MCQs | Topic 11 (Induction) Final Quiz | Quick IB Specific Mixed MCQs | |||
Mr. G | 11.1 Formative Assessment | Topic 11 Summary Qs | IB Specific Questions | |||
Physics and Maths Tutor | E & B Fields (Edexcel 2) | E & B Fields MS (Edexcel 2) | E & B Fields (OCR) | E & B Fields MS (OCR) | A-Level Qs: overlapping content | |
Physics and Maths Tutor | MCQ Magnetic Fields 1 (AQA 2) | MCQ Magnetic Fields 1 MS (AQA 2) | MCQ Magnetic Fields 2 (AQA 2) | MCQ Magnetic Fields 2 MS (AQA 2) | A-Level Qs: overlapping content |
Magnetic Flux and Flux Linkage
There are a few key terms we need to get to grips with to understand this topic. When we discussed magnetic fields back in Section 5.4, we introduced the term 'Magnetic Flux Density' to mean the same thing as 'Magnetic Field Strength'. When thinking about those magnetic field diagrams the flux density can be thought of as how close those field lines are together, i.e the density of the lines of flux per unit area.
Video Lessons
Chris Doner | EM Induction (Flux) | IB Specific | ||||
Khan Academy | Flux | |||||
Science Shorts | Flux Intro |
Resources
IB Physics | Topic 11 Notes | |||||
IB-Physics.net | Chapter 11 Summary | IB Revision Notes | ||||
Isaac Physics | Magnetic Flux | Gauss Law | Extension : Gauss Law beyond IB | |||
Mr. G | 11.1 Teaching Notes | 11.1 Student Notes | ||||
Physics and Maths Tutor | Fields Definitions | Fields Key Points | Fields Detailed Notes | B Field Flashcards | A Level Resources - content slightly different |
Questions
Cambridge University Press | Topic 11: MCQs | CUP Website Link | Freely available online | |||
Dr French's Eclecticon | Electromagnetism | Electromagnetism Solutions | Link to Dr French's Site | Extension: Pre-University Material | ||
Grade Gorilla | 11.1 (Induction) MCQs | Topic 11 (Induction) Final Quiz | Quick IB Specific Mixed MCQs | |||
Isaac Physics | Magnetic Flux and Faraday's Law | Mixed Questions | ||||
Mr. G | 11.1 Formative Assessment | Topic 11 Summary Qs | IB Specific Questions | |||
Physics and Maths Tutor | Flux Density (AQA 2) | Flux Density MS (AQA 2) | Flux & Flux Linkage (AQA 2) | Flux & Flux Linkage MS (AQA 2) | A-Level Qs: overlapping content |
Faraday's Law of Electromagnetic Induction
Video Lessons
Chris Doner | EM Induction (Faraday's Law) | IB Specific | ||||
Gradepod | Faraday's Law | AC Generators | IB Specific | |||
Khan Academy | Faraday's Law Intro | |||||
Science Shorts | Induced EMF and Faraday |
Resources
IB Physics | Topic 11 Notes | |||||
IB-Physics.net | Chapter 11 Summary | IB Revision Notes | ||||
Isaac Physics | Faraday's Law | |||||
Mr. G | 11.1 Teaching Notes | 11.1 Student Notes | ||||
Physics and Maths Tutor | Fields Definitions | Fields Key Points | Fields Detailed Notes | B Field Flashcards | A Level Resources - content slightly different |
Questions
Cambridge University Press | Topic 11: MCQs | CUP Website Link | Freely available online | |||
Dr French's Eclecticon | Electromagnetism | Electromagnetism Solutions | Link to Dr French's Site | Extension: Pre-University Material | ||
Grade Gorilla | 11.1 (Induction) MCQs | Topic 11 (Induction) Final Quiz | Quick IB Specific Mixed MCQs | |||
Isaac Physics | Magnetic Flux and Faraday's Law | |||||
Mr. G | 11.1 Formative Assessment | Topic 11 Summary Qs | IB Specific Questions | |||
Physics and Maths Tutor | MCQ Magnetic Fields 1 (AQA 2) | MCQ Magnetic Fields 1 MS (AQA 2) | MCQ Magnetic Fields 2 (AQA 2) | MCQ Magnetic Fields 2 MS (AQA 2) | A-Level Qs: overlapping content | |
Physics and Maths Tutor | Electromagnetism (Edexcel 1) | Electromagnetism MS (Edexcel 1) | EM Induction (AQA 1) | EM Induction MS (AQA 1) | A-Level Qs: overlapping content | |
Physics and Maths Tutor | E & B Fields (Edexcel 2) | E & B Fields MS (Edexcel 2) | E & B Fields (OCR) | E & B Fields MS (OCR) | A-Level Qs: overlapping content |
Lenz's Law
Lenz's Law tells us all about the direction of the induced EMF described by Faraday. It essentially all comes back to the conservation of energy. Before we look in more detail, I'll leave it to VSauce to introduce things (his MRI demo is my favourite).
Video Lessons
Chris Doner | Lenz's Law | IB Specific | ||||
Khan Academy | Lenz's Law | Faraday's Law & Generators | Faraday's Law example | |||
Science Shorts | Lenz's Law |
Resources
IB Physics | Topic 11 Notes | |||||
IB-Physics.net | Chapter 11 Summary | IB Revision Notes | ||||
Isaac Physics | Lenz's Law Introduction | |||||
Mr. G | 11.1 Teaching Notes | 11.1 Student Notes | ||||
Physics and Maths Tutor | Fields Definitions | Fields Key Points | Fields Detailed Notes | B Field Flashcards | A Level Resources - content slightly different |
Questions
Cambridge University Press | Topic 11: MCQs | CUP Website Link | Freely available online | |||
Grade Gorilla | 11.1 (Induction) MCQs | Topic 11 (Induction) Final Quiz | Quick IB Specific Mixed MCQs | |||
Mr. G | 11.1 Formative Assessment | Topic 11 Summary Qs | IB Specific Questions | |||
Physics and Maths Tutor | E & B Fields (Edexcel 2) | E & B Fields MS (Edexcel 2) | E & B Fields (OCR) | E & B Fields MS (OCR) | A-Level Qs: overlapping content | |
Physics and Maths Tutor | MCQ Magnetic Fields 1 (AQA 2) | MCQ Magnetic Fields 1 MS (AQA 2) | MCQ Magnetic Fields 2 (AQA 2) | MCQ Magnetic Fields 2 MS (AQA 2) | A-Level Qs: overlapping content | |
Physics and Maths Tutor | Electromagnetism (Edexcel 1) | Electromagnetism MS (Edexcel 1) | EM Induction (AQA 1) | EM Induction MS (AQA 1) | 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)
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.