Ch+19+-+Magnetism


 * Chapter 19: Magnetism **//In this chapter concepts such as magnets,// //magnetic fie////lds, magnetic forces, current and magnetism, motion of charged particles in a magnetic field, and magnetic fields of the following: ampere's law, parallel conductors, current loops, and solenoids.//

**Magnets:** __Magnetic Poles__- points in a field that ends of a magnet are strongly attracted to (minimum of two poles) - A use of the earth's magnetic field can be easily related to a compass. The needle of the compass will always be pointing towards the earth's natural north direction.
 * There are two different poles (north and south); they get their name from how magnets react in the earth's magnetic field
 * Opposite poles attract each other and like poles repel each other (just like charges in chapter 15 with charge objects)
 * Though like electric charges if a permanent magnet is cut it still hold a magnetic charge where electric charges can be isolated

**Magnetizing an Object:** __Conduction__ (stroking)- Just how electric charges can be created through conduction, an object can become magnetized by striking it with a magnetized object __Induction__- if a permanent magnet is brought near a piece of unmagnetized material, the piece will eventually become magnetized __DC Current__ - (Direct Current) - the unidirectional flow of an electric charge. Using this type of current can bring an object to be magnetized. Of course, the object must be able to be magnetized.

**Demagnetizing an Object:** __Hammer(banging), heating, and AC Current__ **Types of Materials:** Whether a material is easily magnetized or not depends on whether it's classified as magnetically soft or hard:
 * __Soft__- easily magnetized materials and these materials tend to loose their magnetism easily
 * Iron,
 * __Hard__- difficult to magnetize, but hold their magnetism fairly well
 * Nickel, Cobalt
 * __Ferromagnetic__- strongly attracted
 * Iron, Cobalt, Nickel, Steel
 * __Paramagnetic__- weakly attracted
 * Aluminum, Copper
 * __Diamagnetic__- repelling
 * Gold, Water, Glass

**Earth's Magnetic Field:** The earth's geographical north pole refers to its magnetic south pole and its geographical south pole refers to its magnetic north pole The magnetic poles, axis, and equator are roughly a little bit off of the geographical lines by a couple of degrees. Always remember that the earth's magnetic field runs from north to south.

**Magnetic Field (B Field): (Images are the display the formation of the magnetic field created by the bar magnets.)** - The picture on the left shows the magnetic field of a single bar magnet. Notice how most of the iron filings are clumping on the two extremes of the magnet. - The picture on the right shows the effect of two unlike poles facing each other. The north end is attracted to the south end and it can be seen by the alignment of the iron filings. - The image below shows the effect that two like poles have on the iron filings. The formation shows the repelling forces. __Magnetic Field__- a magnetic force that exists around a magnetized object that affects other objects around it //when moving through a magnetic field, a charged particle experiences a magnetic force// __Field Lines__- just as in electric field the magnetic field around objects is shown with lines displaying the vector and direction __Compass__- can be used in aid with iron filings to find electric field lines (needle always points to the earths magnetic south pole)

- The following image uses the explained field lines to illustrate the magnetic field of a loop. The magnetic field comes up through the center of the loop and around the edges as shown.

Magnetic Force (F; in newtons) can be determined by: Magnetic Field (B; measured in Tesla(T) or Weber (Wb) per unit squared, 1T=1Wb/m^2) can be determined by: //For both equations// B represents field (Tesla), F represents force (Newtons), q represents test charge (Coulombs), v represents velocity (m/s), and θ the angle between the direction of velocity and the direction of field
 * F=qvBsinθ
 * B=(F)/(qvsinθ)

***This final image is a crucial aspect to understanding the direction a magnetic field or force moves. The thumb represents the direction of the current. The middle finger** **is the force and last but not least the index finger points in the direction of the magnetic field.***