Magnetism

What makes a magnet? Some materials align their unpaired electrons so they spin all in the same direction. These electrons form microscopic clusters called Domains When the domains are lined up in one direction, a magnet is formed.

Magnetic Force Force of attraction or repulsion between magnetic poles

Magnetic Fields Similar to Gravitational and Electrostatic Fields Representation of this field is called Magnetic Flux Strength of the field is called Magnetic Induction, or Flux Density (B)

Magnetic Flux Lines NS NS SS

N S

Electromagnetism A wire carrying a current produced a magnetic field The direction of the magnetic field is found by using the Right Hand Rule

Right Hand Rule The Thumb points in the direction of the current. The fingers wrap around in the direction of the Magnetic Field The Thumb points in the direction of the magnetic field, N pole. The fingers wrap around in the direction of the current

Right Hand Rule Representation

Electric Meters Galvanometer – Used to measure small electric currents. Measures the torque or force that produces rotational motion, of a wire. – An ammeter is a galvanometer that has been modified to measure large currents – A voltmeter is a galvanometer that has been modified to measure potential differences