Saturday, January 21, 2012

Magnetism: Electromagnetism + Right Hand Rule #1

Current: the transfer of positive charge; the opposite of electron flow.
Electromagnetism: the interactions between electric currents and magnetic fields

Background Information
  • In 1819, a Danish physicist named Hans Oersted discovered that a current-carrying conductor caused a magnetic compass to deflect. This led him to be credited for the discovery of electromagnetism.
  • Electromagnetic fields can be created by the movement of charges, but not by static charges.

Right hand rule #1

Thumb points toward the current, fingers encircling the conductor in the direction of the magnetic lines of force

Magnetic Field Theory 
  • Magnetic field is the source of magnetic forces
  • A current creates a magnetic field around itself 
  • The strength of the magnetic field is directly related to the strength of the current

Magnetic Field of a Current-Carrying coil

Arrow is the direction of the current; x's are the magnetic  fields coming into the page; dots are the magnetic field coming out of the page
As shown in the picture, the field inside the loop is stronger than the field outside of the loop. Also, the field is more uniformed inside the loop