Simple Phenomena Of Magnetism
Overview
A magnet can pull a paperclip across a desk without touching it, and a compass needle swings to point north on its own. Behind both is a magnetic field, an invisible region of influence that you can map, explain and put to work in everything from doorbells to electric motors.
In this lesson you will learn the rules of attraction and repulsion between poles, the difference between magnetic and non-magnetic materials and between temporary and permanent magnets, how to draw and plot a magnetic field, and where permanent magnets and electromagnets are used.
Objectives
- Describe the forces between magnetic poles and between magnets and magnetic materials, including the use of the terms north pole (N pole), south pole (S pole), attraction and repulsion, magnetised and unmagnetised
- Describe induced magnetism
- State the differences between the properties of temporary magnets (made of soft iron) and the properties of permanent magnets (made of steel
- State the difference between magnetic and non-magnetic materials
- Describe a magnetic field as a region in which a magnetic pole experiences a force
- Draw the pattern and direction of magnetic field lines around a bar magnet
- State that the direction of a magnetic field at a point is the direction of the force on the N pole of a magnet at that point
- Describe the plotting of magnetic field lines with a compass or iron filings and the use of a compass to determine the direction of the magnetic field
- Describe the uses of permanent magnets and electromagnets
- [Supplement] Explain that magnetic forces are due to interactions between magnetic fields
- [Supplement] Know that the relative strength of a magnetic field is represented by the spacing of the magnetic field lines
Lesson Note
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Lesson Evaluation
Congratulations on completing the lesson on Simple Phenomena Of Magnetism. Now that youve explored the key concepts and ideas, its time to put your knowledge to the test. This section offers a variety of practice questions designed to reinforce your understanding and help you gauge your grasp of the material.
You will encounter a mix of question types, including multiple-choice questions, short answer questions, and essay questions. Each question is thoughtfully crafted to assess different aspects of your knowledge and critical thinking skills.
Use this evaluation section as an opportunity to reinforce your understanding of the topic and to identify any areas where you may need additional study. Don't be discouraged by any challenges you encounter; instead, view them as opportunities for growth and improvement.
- Which test reliably shows that a bar is magnetised? A. it is attracted by a magnet B. it repels one end of a known magnet C. it is made of iron D. it is heavy Answer: B
- Magnetic field lines around a bar magnet point: A. from S pole to N pole B. from N pole to S pole C. in random directions D. in circles only Answer: B
- Which material is best for the core of a switchable electromagnet? A. steel B. copper C. soft iron D. plastic Answer: C
- Where is a magnetic field strongest around a bar magnet? A. in the middle B. where the field lines are closest together C. far from the magnet D. where the lines are furthest apart Answer: B
- Which is a non-magnetic material? A. iron B. steel C. cobalt D. copper Answer: D
Available on the Green Bridge App
Download the Green Bridge CBT app on your phone or computer to access full lesson notes, practice questions, and more.
Available on the Green Bridge App
Download the Green Bridge CBT app on your phone or computer to access full lesson notes, practice questions, and more.
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