Oersted discovered that electric currents create magnetic fields by observing that a compass needle deflected when placed near a wire with a current. He established that a moving electric charge produces a circular magnetic field around the conductor. The right-hand rule determines the direction of this magnetic field based on the direction of current flow. Oersted's findings led to new technologies like motors and generators by demonstrating the control of magnetic fields using electricity.

1. oersted’s discovery

2. oersted’s experiment
• successfully connected
electricity and magnetism
• aligned a straight wire with a compass
pointing to Earth’s magnetic north
• when current is present, the needle deflects
perpendicular to the wire
• when the current is reversed, the needle
deflects in the opposite direction

3. oersted’s principle
• “a charge moving through a straight
conductor produces a circular magnetic field
around the conductor”

4. the right hand rule
• to determine the direction of the magnetic field
around a straight current-carrying conductor, use
the right-hand rule:
– if you hold a straight conductor in your right hand
with your right thumb pointing in the direction of the
conventional current, your curled fingers will point in
the direction of the magnetic field lines
– note: if you use the electron flow model instead, you
must use your left hand

5. representing currents and magnetic
fields
• a cross-section of the wire is often shown
• the current can either go into the page (x) or
out of the page ()
• this model is based on an arrow
• the magnetic fields get farther apart as you
move away from the wire to indicate that it is
getting weaker

6. implications
• led to new technologies like motors and
generators
• demonstrated using electricity to produce
magnetism
• can produce magnetic fields with properties that
can be controlled:
– can turn the magnetism on and off
– can change the direction of the magnetic field
– can change the strength of the magnetic field

7. implications
• led to new technologies like motors and
generators
• demonstrated using electricity to produce
magnetism
• can produce magnetic fields with properties that
can be controlled:
– can turn the magnetism on and off
– can change the direction of the magnetic field
– can change the strength of the magnetic field