1. Electric Currents,
Magnetic Fields
October 16, 2013

2. Objectives
1.
Describe the magnetic field produced by a
current-carrying wire
2.
Give examples of how the field can be
made stronger

3. We KNOW
 Electric wire can be made to have a current
 Magnet has a magnetic field surrounding it

4. Interaction
 An electric current produces a magnetic field
 Magnetic field makes up a pattern of circles

5.  When the current is reversed the direction of the
magnetic field is also reversed
 If a current carrying wire is looped the magnetic
field is intensified
 More loops means greater magnetic field

6. Electromagnets
 If a piece of iron is placed in a current-
carrying coil of wire, the iron will become a
magnet – electromagnet (temporary magnet)
 Roller coasters
 Junk yards
 Electric trains

7. Magnetic Forces on Wires
 If an electric current can produce a magnetic
field
 Then, we can use a magnetic field to change
an electric current
 We can use the combination of both to create
a motor