CHAPTER 5

PHYSICS FOR JUNIOR HIGH SCHOOL IX

Magnetic Indication and Making Magnet

PHYSICS FOR JUNIOR HIGH SCHOOL IX

INDICATION OF MAGNETIC

Magnet can pull certain things

PHYSICS FOR JUNIOR HIGH SCHOOL IX

MAGNETIC INDICATION

ORIGIN OF MAGNET Word “magnet” comes

from magnesia, that is a name of an area at small Asia, where was founded iron stone more than 2000 years ago.

Chinese nation have used magnetic compas as direction in sailing since 1200.

PHYSICS FOR JUNIOR HIGH SCHOOL IX

INDICATION OF MAGNETICCOMPOSITION OF MAGNETIC AND NON MAGNETIC Composition of magnetic:

composition that can be strongly pulled by magnet can be magneted. E.g.: iron, steel, nickel, cobalt

Composition of Non-magnetic, : Composition of paramagnetic,

composition that can be weakly pulled by magnet and cannot be magneted. E.g.: aluminum, platinum

Composition of diamagnetic,Composition that can be weakly

pushed bymagnet and cannot be magneted. E.g.: zinc, bismuth

PHYSICS FOR JUNIOR HIGH SCHOOL IX

MAGNETIC EFFECT

Magnet pole is tips of magnet that have big trade offs force and repellence. Each magnet has two pole, north pole ( N ) and south pole (S).

Magnet has Two Pole

PHYSICS FOR JUNIOR HIGH SCHOOL IX

MAGNETIC EFFECTCHARACTERISTICS OF MAGNET POLE

Different pole will trade-offs Same pole will repellence

PHYSICS FOR JUNIOR HIGH SCHOOL IX

HOW TO MAKE MAGNET

1. Rubbing

Rubbing magnet regularly at iron and armor, hence iron and armor will have magnetic characteristic.

Magnet pole is different with pole of synthetic magnet.

PHYSICS FOR JUNIOR HIGH SCHOOL IX

HOW TO MAKE MAGNETUsing Electromagnetic

Magnet pole can be determined by right hand method:

• four hand = electromagnetic direction ( I )• thumb = north pole direction ( N )

PHYSICS FOR JUNIOR HIGH SCHOOL IX

HOW TO MAKE MAGNET3. INDUCTION

If an iron or armor are brought nearer (don’t touch) to strong magnetic object, so the iron or armor will be magnet. The process is called induction.If the iron is separated from the object, magnetic of iron will loss its characteristic, but armor will held it.

PHYSICS FOR JUNIOR HIGH SCHOOL IX

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