Magnetic Force Fields – Physics Class Notes Day 1

Introduction To Magnetic Force and Fields

The discovery of magnetic force and fields can be trace back to 600 B.C. by the Greeks. The discovery was that lodestone attracted small peices of iron, and when placed closely the peices of iron would rotate and come to rest in a north-south position.

Magnetic Poles:

Magnets have areas where highest level of force is concentrated called poles, this is where most attractions occurs. Consider when a magnetic is dipped in iron filling, the filling are attracted to the magnet and accumulate most noticeably at the oppposite ends. A magnet has two opposite poles: N-pole (north-seeking pole) and S-Pole (South-seeking pole).

Law of Magnetic Poles:

• Opposite magnetic poles attract.
• Similar Magnetic poles repel.

Magnetic Field of Force:

Magnets are known to have a field of force given that they affect objects at a distance. This type of foce is similar to gravatational force and eletric force.

Magnetic field is represented by a series of lines around a magnet. The magnetic field line indicated the direction in which the N-pole of the test compass would point.

Characterisitcs of magnetic field:

1. The spacing of the lines indicated the relative force. The closer together lines are, the greater the force.
2. Lines are concentrated at the poles,
3. Lines proceeds from S to n inside a magnet and from N to S outside a magnet, forming closed loops.
4. Lines do not cross.