Download Electricity, Magnetism, and Motion

Electricity, Magnetism,
and Motion
Chapter 3 Section 2
Pages 85 - 89
Objective: Explain how electrical energy is converted
into mechanical energy and vice versa.
Energy: Ability to move an object some distance.
Electrical Energy: Energy associated with electrical
currents.
Mechanical Energy: Energy an object has due to its
movement or position.
When a wire with a current is placed in a magnetic
field, electrical energy is transformed into
mechanical energy.
Galvanometer: Used to measure small currents. It is
a device that uses the rotation of a loop of wire in a
magnetic field. The electric current turns the pointer
Electric Motor: A device that uses an electric current
to turn an axle.
*An electric motor converts electrical energy into
Mechanical energy. Electricity produces motion!
How can you make a loop of wire continue to spin?
Current is reversed just as the loop gets to the vertical
position. This reverses the direction of the movement of both
sides of the loop. The current reverses after each half turn so
the loop spins continuously in one direction.
Parts of a motor:
Commutator: A device that reverses the flow of
current through the electric motor.
Brushes: Contact points where each half of the
commutator gets its electric current.
Armature: An arrangement of wires and iron core.