Current Carrying Conductors
chapter 11
lesson 2
Objective
You will be able to describe the
interactions of the magnetic fields in
conductors.
Ampere investigated the interaction
between two current-carrying wires
parallel to each other.
How would these magnetic fields react in
the wires shown, with current indicated by
the letter I?
Definition of an Ampere
If two wires, each one meter long and one meter
apart, carry current so that the force between
the two wires is 2.00 x 10-7 N, the current in each
wire is one ampere.
Magnetic Fields in Solenoids (coils)
When current flows through each loop of wire in a
coil a magnetic field is set up in such a way that it
makes the coil act like a single bar magnet.
Second Left Hand Rule
Fingers curl around the coil in the direction of the
current flow.
Outstretched thumb points to the end of the coil that
acts as the north end of a fixed magnet.
Electromagnets
A solenoid can be made to be a much stronger
magnet by placing a ferromagnetic material
(usually steel) inside the coil.
Electromagnets have many uses.
Magnetizing ferromagnetic material
Bells
Relay switches
Electric Bell
Railguns
Repelling magnetic fields accelerate projectile
Watch this
http://www.youtube.com/watch?v=dEe4NaStnIg