57.58_Magnetic Properties of Materials
Оценка 4.9

57.58_Magnetic Properties of Materials

Оценка 4.9
ppt
08.05.2020
57.58_Magnetic Properties of Materials
57.58_Magnetic Properties of Materials.ppt

Lesson Objectives By the end of the lesson learners will be able: 10

Lesson Objectives By the end of the lesson learners will be able: 10

Lesson Objectives

By the end of the lesson learners will be able:

10.4.1.3 – to describe modern scopes of using magnetic substances (neodymium magnets, sensors, seismographs, metal detectors) and to discuss the tendency of their application;

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Keywords English Russian Kazakh

Keywords English Russian Kazakh

Keywords

English

Russian

Kazakh

Soft magnetic materials

Hard magnetic materials

Paramagnetic

Ferromagnetic

Diamagnetic

Magnetic materials

magnetization

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Types of Magnetic Materials Magnetic:

Types of Magnetic Materials Magnetic:

Types of Magnetic Materials

Magnetic: Can be magnetized and are attracted to magnets

Non-magnetic: Cannot be magnetized e.g. brass, copper, zinc, tin, aluminium, non-metals

Ferromagnetic: Strongly attracted by a magnetic field: iron, nickel, cobalt

Paramagnetic: Slightly attracted by a magnetic field: magnesium, molybdenum, lithium, tantalum

Diamagnetic: slightly repelled by a magnetic field: copper, silver, gold

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Explain these terms Field: Magnetic

Explain these terms Field: Magnetic

Explain these terms

Field:

Magnetic Flux Density:

Magnetic Flux:

Magnetization:

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Explain these terms Field: Region where magnetism is experienced

Explain these terms Field: Region where magnetism is experienced

Explain these terms

Field: Region where magnetism is experienced

Magnetic Flux Density: Number of magnetic lines of force cutting through a plane of given area at right angle.

Magnetic Flux: Total number of lines of magnetic force in a material

Magnetization: Is a measure of the extent to which an object is magnetized

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Activity 1 Where does Magnetism come from? 8-May-20 7

Activity 1 Where does Magnetism come from? 8-May-20 7

Activity 1

Where does Magnetism come from?

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Where does Magnetism come from?

Where does Magnetism come from?

Where does Magnetism come from?

Each electron in an atom has a magnetic effect as it spins and orbits the nucleus.
Magnetic effects of the electrons cancel out in many atoms, some no, and atoms act like tony magnets called dipoles.
In unmagnetised state , the atomic magnets point in random directions.
In a fully magnetized state, more and more atomic magnets line up with each other.
Billions of tiny atomic magnets act as one big magnet
= Domain Theory.


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Dipole Arrangements 8-May-20 9

Dipole Arrangements 8-May-20 9

Dipole Arrangements

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Magnets and Magnetic Materials

Magnets and Magnetic Materials

Magnets and Magnetic Materials

Magnets attract objects made of magnetic materials

Magnetic materials include the elements iron, nickel, cobalt,
alloys containing some of these such as steel and some of their compounds.

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More Sizes and Shapes 8-May-20 11

More Sizes and Shapes 8-May-20 11

More Sizes and Shapes

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Magnadur Magnets 8-May-20 12

Magnadur Magnets 8-May-20 12

Magnadur Magnets

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Quantifying Magnetic Properties

Quantifying Magnetic Properties

Quantifying Magnetic Properties

Quantity

Symbol

SI Units

Field

H

A/m

Flux Density

B

tesla

Flux

Φ

weber

Magnetization

M

A/m

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Hard and Soft Magnetic Materials

Hard and Soft Magnetic Materials

Hard and Soft Magnetic Materials

Permanent magnets are made of magnetically HARD materials such as steel, alcomax, magnadur. These materials retain their magnetisation once magnetised. Hard to magnetise.

Magnetically SOFT materials, such as iron, mumetal lose their magnetisation easily. They suitable for temporary magnets such as electromagnets. Easy to magnetise.

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Magnetic Poles Magnetic poles are the parts of a magnet that exert the greatest force

Magnetic Poles Magnetic poles are the parts of a magnet that exert the greatest force

Magnetic Poles

Magnetic poles are the parts of a magnet that exert the greatest force.

Magnetic poles occur in pairs usually called north (N) and south (S)

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Why North and South Poles? A magnet suspended so that it can rotate freely horizontally will eventually settle down with one pole facing north and…

Why North and South Poles? A magnet suspended so that it can rotate freely horizontally will eventually settle down with one pole facing north and…

Why North and South Poles?

A magnet suspended so that it can rotate freely horizontally will eventually settle down with one pole facing north and the other south.

This pole pointing north is therefore called the ‘north seeking pole’, usually shortened to just ‘north pole’.

The magnet has been orientated by the Earth’s magnetic field.

A compass is an application of this effect.

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The Law of Magnets Like poles repel unlike poles attract

The Law of Magnets Like poles repel unlike poles attract

The Law of Magnets

Like poles repel unlike poles attract.
The closer the poles, the greater the force between them.

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Task A , B , C , and D are small blocks of different materials

Task A , B , C , and D are small blocks of different materials

Task

A, B, C, and D are small blocks of different materials. The table below shows what happens when two of the blocks are placed near one another. Say whether the block is a magnet, a magnetic material or anon magnetic material.

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Arrangement of blocks

Effect

A near B

attraction

B near C

A near C

No effect

B near D

Properties of Magnets Has a magnetic field around it

Properties of Magnets Has a magnetic field around it

Properties of Magnets

Has a magnetic field around it
Has two opposite poles( N and S ) which exert forces on other magnets.
Will attract magnetic materials by inducing magnetism in them
Will exert little or no force on a non magnetic material.

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Fill in the gaps below: Magnetic materials are either hard or ______

Fill in the gaps below: Magnetic materials are either hard or ______

Fill in the gaps below:
Magnetic materials are either hard or ______. Hard magnetic materials such as ______ retain their magnetisation once magnetised.
A magnetic _____ is a region where the magnetic force is greatest. Magnetic poles always occur in ______. Like poles _______, unlike attract.
A magnetic ______ is a region where magnetic force is exerted. The ________ of the magnetic field around a bar magnet is from north to south.

soft

repel

field

steel

direction

pole

pairs

WORD SELECTION:

soft

repel

field

steel

direction

pole

pairs

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Magnetic Properties of Materials 8-May-20 21

Magnetic Properties of Materials 8-May-20 21

Magnetic Properties of Materials

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Complete the table 8-May-20 22

Complete the table 8-May-20 22

Complete the table

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Material

Magnetic Field

Magnetic Force

Permeability

Ferromagnetic

Paramagnetic

Diamagnetic

Key Summary 8-May-20 23

Key Summary 8-May-20 23

Key Summary

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Activity Explain the applications of:

Activity Explain the applications of:

Activity

Explain the applications of:
Neodymium magnets
Sensors
Seismographs
Metal detectors

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