BACKGROUND:
Students have heard the words volt,
watt, and amps, but few know what they refer to. These terms all have to
do with the flow of electricity. A volt is a force of electricity that
goes through a conductor. For instance, a 1.5 volt battery has less
force than a 6-volt battery. Houses in the United States have 110 volts
coming through the wall socket which is much more force than the
batteries. Students are told not to play with the sockets in the wall
because of this extra force. Volt is named after Alessandro Volta, an
Italian physicist.
An ampere is the measurement of
electric current, named after Andre Marie Ampere, a French physicists.
Fuses are designed to carry so many amperes. When a system carries too
much amperage, it will "blow a fuse." This happens when too
many amperes go through the system and this alerts you to decrease power
usage.
A watt is the measurement of power. A
100-watt bulb is brighter than a 30-watt bulb. It was named for James
Watt, a Scottish engineer and inventor. Many times you will see the term
hertz on electrical appliances. This refers to the frequency of the
current going through in a cycle. Hertz was named for a German
physicist.
PROCEDURE:
- For the first exercise, find
several appliances where the students can find either the watts or volts
and amps the appliance uses.
- Students may bring in small
electrical appliances for this exercise. The more the watts or volts or
amps, the more electricity is used.
- Have students determine which
appliance uses the most energy. This will depend on the appliances you
have. Volts and amps are related to watts: watts = volts x amperes. Have
students record the watts, volts and amperes that they determine from
the appliance.
