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# 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

Lenz's Law - where does the force opposing motion come from?

Inducing an EMF

#### 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

## 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

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