Physics116Updated 12 Oct 20265 pages

Magnetism and Electromagnetism Explained

Report
user profile picture
Charlotte@charlotte26
Magnetism is everywhere around us - from the magnets on your fridge to the motors in your phone's vibration. Understanding how magnets work and how electricity can create magnetic fields opens up a whole world of physics that powers most of the technology you use every day.
Magnetism and electromagnetism – page 1

Sign up to see the content.
It's free!

By signing up you accept Terms of Service and Privacy Policy

Magnetism Basics

Think of magnets as having two distinct personalities at opposite ends - the north pole and south pole. Just like people, opposites attract whilst similar personalities clash.

Like poles repel (N-N or S-S push away from each other) whilst unlike poles attract (N-S pull together). The magnetic force is strongest right at the poles and works as a non-contact force - meaning magnets don't need to touch to affect each other.

Only certain metals respond to magnets: iron, steel, cobalt and nickel. These are called magnetic materials, and they're the reason your steel scissors stick to a magnet but your plastic ruler doesn't.

Key Tip: The magnetic force gets weaker as you move further from the poles - that's why magnets work best when they're close together.

Magnetism and electromagnetism – page 2

Sign up to see the content.
It's free!

By signing up you accept Terms of Service and Privacy Policy

Types of Magnets

Permanent magnets are like that reliable friend who never changes. Made from magnetic materials, they always maintain their magnetic properties and constantly produce their own magnetic field.

Induced magnets are more like fair-weather friends - they only become magnetic when placed near another magnet. Remove the magnetic field, and they quickly lose their magnetism.

This difference explains why some materials become temporarily magnetic when near a magnet but return to normal when moved away.

Remember: Permanent magnets keep their magnetism; induced magnets only "borrow" it temporarily.

Magnetism and electromagnetism – page 3

Sign up to see the content.
It's free!

By signing up you accept Terms of Service and Privacy Policy

Magnetic Fields and Testing

To test if something is truly magnetic, try this: a permanent magnet can both attract AND repel other magnets, but it can only attract magnetic materials. If it repels, you've definitely got a magnet on your hands.

Magnetic fields are invisible areas around magnets where their force operates. We can detect these using a magnetic compass - essentially a tiny bar magnet that rotates to point towards magnetic north.

Electromagnets (also called solenoids) are brilliant because you can switch them on and off. They're made by wrapping wire in a coil and passing current through it. Add an iron core, and you've massively boosted the magnetic field strength.

Cool Fact: Earth itself is like a giant magnet with an iron and nickel core, which is why compasses work!

Magnetism and electromagnetism – page 4

Sign up to see the content.
It's free!

By signing up you accept Terms of Service and Privacy Policy

The Motor Effect and Electric Motors

The motor effect might sound complicated, but it's actually quite straightforward - when you pass current through a wire in a magnetic field, the wire experiences a force that pushes it at right angles.

This force follows the equation: force = magnetic flux density × current × length. More current or stronger magnetic field equals more force.

Electric motors use this principle brilliantly. A coil of wire sits in a magnetic field, and when current flows through it, the coil rotates. The clever bit is the commutator - it switches the current direction every half turn, keeping the motor spinning in the same direction.

Real-World Connection: This same principle powers everything from your electric toothbrush to electric cars!

Magnetism and electromagnetism – page 5

Sign up to see the content.
It's free!

By signing up you accept Terms of Service and Privacy Policy

Fleming's Left Hand Rule and Transformers

Fleming's left hand rule is your go-to memory aid for working out directions in the motor effect. Your thumb shows movement direction, forefinger shows the magnetic field (north to south), and your second finger shows current direction (positive to negative).

The force is strongest when current flows at 90° to the magnetic field. If they're parallel, there's no motor effect at all.

Transformers are incredibly useful devices that change voltage in alternating current. They use two coils wound around an iron core - when alternating current flows through the primary coil, it creates a changing magnetic field that induces a different voltage in the secondary coil.

Essential Knowledge: Transformers only work with alternating current because they need the constantly changing magnetic field to function.

We thought you’d never ask...

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.

Similar content

Physics

Understanding Magnetism

Explore the fundamental concepts of magnetism, including magnetic poles, forces, and fields. This summary covers the types of magnets, the rules of attraction and repulsion, and the distinction between permanent and induced magnets. Ideal for physics students seeking to grasp the essentials of magnetism.

111112
Physics

Physics Paper 2 Overview

Explore key concepts in magnetism, forces, and waves for Physics Paper 2. This comprehensive summary covers Newton's Laws, electromagnetic waves, the motor effect, and practical experiments. Ideal for exam preparation and understanding core principles in physics.

113165
Physics

Comprehensive Physics Overview

Explore key concepts in AQA GCSE Physics, including magnetism, gravity, radioactivity, electricity, waves, and energy transfer. This summary covers essential topics for Paper 1 and 2, providing a clear understanding of forces, fields, and the behavior of matter. Ideal for exam preparation and revision.

112557
Physics

Forces and Waves Overview

Explore key concepts in physics including contact and non-contact forces, elasticity, moments, fluid pressure, wave types, and the life cycle of stars. This summary provides essential formulas and principles for understanding motion, energy transfer, and the behavior of light. Ideal for foundation physics revision.

114,477157
Physics

Electricity and Circuits Overview

Explore key concepts in electricity and circuits, including static electricity, current, resistance, and circuit configurations. This summary covers essential topics such as Ohm's Law, series and parallel circuits, and the behavior of electrical components. Ideal for AQA GCSE students preparing for exams.

1173330
Physics

Waves: Slit Experiments Explained

Explore the principles of single-slit diffraction and the double-slit experiment in AQA A Level Physics. This summary covers key concepts such as wave-particle duality, diffraction, and wave interference, providing clear diagrams and explanations to enhance your understanding.

123913

Most popular content: Physics

Physics

Forces and Motion Overview

Explore key concepts in Forces and Motion, including Hooke's Law, velocity, acceleration, and the principles of moments. This summary covers essential topics such as the relationship between force and extension, terminal velocity, and the impact of safety devices in physics. Ideal for AQA Physics Unit 5 revision.

109,435876
Chemistry

BTEC Applied Science Unit 1 Overview

Comprehensive resource for Year 12 students pursuing a Level 3 Diploma in Applied Science. This booklet covers essential topics including cell structure, chemical properties, and wave theory, providing clear explanations and key concepts to aid in your studies and exam preparation.

125,674130
Physics

GCSE Physics Notes

GCSE AQA Combined Physics revision notes P2

1185422
Physics

GCSE AQA waves

Grade 9 spec based revision notes for AQA higher triple physics

1156311
Physics

GCSE AQA forces

Grade 9 spec based revision notes for AQA higher triple physics

1158513
Physics

GCSE Physics Practical Experiments

Explore essential GCSE Physics practicals for AQA, covering key concepts such as Hooke's Law, wave properties, thermal insulation, and electrical circuits. This comprehensive guide includes step-by-step procedures, variables, and safety considerations for each experiment, ensuring a thorough understanding of practical applications in physics.

1111,502479
Physics

Electricity Fundamentals

Comprehensive GCSE AQA Physics notes covering key concepts of electricity, including series and parallel circuits, power calculations, resistance, electrostatics, and the National Grid. Ideal for students preparing for exams, this resource provides clear explanations and essential formulas.

116,168569
Physics

Periodic Table Overview

Explore the essential features of the Periodic Table, including atomic structure, groups, and trends. This summary highlights key elements, their atomic numbers, and properties, making it a valuable resource for understanding chemical elements and their classifications. Ideal for students studying chemistry.

112,71777
Physics

Energy Flow Systems

Explore the fundamentals of energy flow diagrams, including energy stores, pathways, and transfers. This summary covers key concepts such as heating, electrical transfer, and the eight energy stores, providing a clear understanding of how energy is measured and transformed in various systems. Ideal for students studying energy principles in physics.

112,697247

Most popular content

Sociology

Sociology of Education Overview

Explore comprehensive A-Level Sociology notes on the education system, covering key theories, policies, and sociological perspectives. This resource includes insights on marketisation, gender roles, cultural deprivation, and educational inequalities, providing a thorough understanding of how education shapes social stratification and individual achievement. Ideal for exam preparation and in-depth study.

12103,7643,053
Sociology

Sociology of Families: Comprehensive Revision

Dive into an extensive overview of family dynamics, perspectives, and patterns in sociology. This resource covers key concepts such as family diversity, gender roles, marriage, and the impact of social policies on family structures. Perfect for A-Level Sociology students preparing for Paper 2.

1274,4402,310
Sociology

Comprehensive Crime & Deviance Overview

Explore an extensive revision of crime and deviance topics, including theories, types of crime, and the impact of media. This resource covers key concepts such as Marxism, functionalism, gender and crime, and the influence of globalization on criminal behavior. Ideal for students seeking a thorough understanding of criminology and its various theories. Type: Full Topic Revision.

1252,2651,413
English Literature

An Inspector Calls: Character Insights

Explore in-depth analysis and key quotes for characters in J.B. Priestley's 'An Inspector Calls'. This resource covers Gerald Croft, Inspector Goole, Sheila Birling, Mrs. Birling, Eric Birling, and Eva Smith, focusing on themes of class, gender roles, and social responsibility. Ideal for students aiming for Grade 8 and above.

1126,232925
Biology

AQA Biology: Key Concepts

Explore essential AQA Biology topics including Photosynthesis, Respiration, Homeostasis, Genetics, and Ecology. This comprehensive knowledge organizer covers key concepts such as energy transfer, hormonal control, and genetic variation, providing a solid foundation for your studies. Ideal for exam preparation and understanding biological processes.

109,576322
Criminology

Criminal Justice Evidence Rules

Explore the essential rules governing the use of evidence in criminal cases, including reliability, admissibility, and relevance. This summary covers key concepts such as the roles of personnel in investigations, the impact of witness testimonies, and the implications of plea bargaining. Ideal for Year 13 criminology students preparing for assessments.

1211,558188
Criminology

Criminal Justice Overview

Explore key concepts in criminal justice, including the trial process, roles of court personnel, types of offenses, and evidence handling. This comprehensive summary covers essential topics such as jury strengths and weaknesses, the role of the CPS, and the impact of media on trials. Ideal for students preparing for assessments in criminology. Achieved a B grade.

133,81579
English Literature

An Inspector Calls: Character Insights

Explore the intricate character dynamics and themes in J.B. Priestley's 'An Inspector Calls'. This analysis covers key characters like Mrs. Birling, Sheila, Eric, and the Inspector, alongside themes of social responsibility, class, and gender inequality. Understand the historical context and Priestley's critique of capitalism. Ideal for students seeking a comprehensive understanding of the play's moral messages.

1113,959700
Sociology

Sociological Theories Overview

Comprehensive revision of key sociological theories including Functionalism, Marxism, Feminism, and Interpretivism. Explore concepts like value freedom, identity formation, and the critique of social control. Ideal for AQA A-Level Sociology students preparing for exams. This summary covers essential theories and their implications in sociology, providing a clear understanding of each perspective.

1232,048853

Students love us, and so will you.

4.6/5App Store
4.7/5Google Play
Stefan SiOS 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.

Samantha KlichAndroid 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.

AnnaiOS 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.