The electric generator and electric
motor are similar because they both use current electricity and
magnetism. The electric motor is essentially an electromagnet that is
made to rotate within a stationary magnet. Electric motors provide power
for all types of machinery, including home appliances. Gas motors also
use electromagnets, but they require a generator to create electrical
sparks for the gas to run the motor. In a car motor, the electrical
energy can be supplied by the generator. A generator converts one form
of energy into another
Magnetic fields are the basis for
electric bells, telephone receivers, radio and television speakers, tape
recorders, and many other items. Electromagnets help control the
intensity of signals as well as being a method of transmittal.
Modern telephone systems rely on
electromagnets. The telephone receiver is basically an electromagnet
with a U_shaped yoke having coils wound on each leg of the U. Passage of
the electrical signal through the coils causes magnetic attraction of a
soft_iron diaphragm supported a small distance from the ends of the U.
The diaphragm generates sound waves as it moves back and forth.
Improvement in magnetic materials has increased the sensitivity of the
telephone receiver, but the basic design has remained unchanged.
The electromagnet has also played a
primary role in research and is an indispensable tool in the quest to
understand the universe by the use of electromagnetic waves.
PROCEDURE:
- Use the enclosed sheet to have
students find the electromagnet in the appliance.
- Answers:
1. In a hand saw you can
find an electromagnet in the motor.
2. In a toaster the electromagnet
helps control the intensity of the coils.
3. The electromagnetic is
found in the motor on this clothes dryer.
4. The electromagnetic is
found in the speaker system and receiver system on a television.
5.
There are no electromagnets in a coffee maker.
6. The receiver and
speaker have electromagnets.
7. There are no electromagnets in a lamp.
8. The electromagnet is in the motor.
9. In an electric screwdriver, the
motor contains the electromagnet .
10. The motor of a car has an
electromagnet. The radio or cellular phone would have an
electromagnetic.
