Physics 12 Magnetism 1 – Introduction Mr. Jean

Magnetics: About 2500 years ago magnetic were discovered by the Greek Army. It was discovered in a part of Turkey called “Magnesia” in English. The rock minerals with these unique properties were called magnetite; over time the word magnet was then derived from this.

Aristotle attributed the first of what could be called a scientific discussion on magnetism to Thales, who lived from about 625 BCE to about 545 BCE. Around the same time, in ancient India, the Indian surgeon, Sushruta, was the first to make use of the magnet for surgical purposes.

What reacts? Not all metals have an interaction with magnetic fields. There are only 5 metals which do: –Nickel –Iron –Cobalt –Magnetite –Gadolinium

Magnetic North: All magnets try to self align with magnetic north and will align themselves provided no strong force is acting on them. The Chinese found that by striking nickel, iron, or Cobalt onto magnetite that these items would pick up the magnetic field. The Chinese were the first to use magnets to navigate in the oceans.

Magnetic Fields:

Ampere’s Law: –Magnetic field’s circulation is proportional to the amount of current being pushed through the wire. –We use the first right hand rule to show the direction of the current as well as the field. Brightstorm: –

Right Hand Rules: Brightstorm: – yshttp:// ys

To do: Complete Right hand rule handout Work on the chapter 15 Pre-test