a clean flat area to do the projects:
It is hard to imagine.
about electricity.
flows in a loop.
Batteries are a source
of electrical energy.
Perhaps using a battery
you have spun a motor,
lit a light bulb or LED,
or buzzed a buzzer.
(1.5 volts)
by a battery is constant.
0
-1
electrons flow in one direction.
This is called
DC for direct current.
for alternating current.
the wall plug alternates.
It is not flat.
It goes UP and DOWN.
whether DC or AC,
can be open or closed.
to open and close a battery-powered
DC circuit.
you can turn a buzzer on and off.
open and close
household circuits.
if they are conductors or insulators?
and a simple parallel circuit?
have you discovered the FUN of exploring electricity?
If you have discovered that,
then you have discovered a great deal, indeed.
were with static electricity -- CHARGE!
a carpet and been shocked when
you touched an object. THAT is
you need to know or recall
that all ordinary matter is made of particles.
with a sharp pencil tip
would have about
four times a billion
times ANOTHER billion
carbon atoms in it!
Now that IS small!
are made of atoms!
How small are atoms
answer.
have a property called:
is made of particles.
in a pencil dot
has a center or nucleus containing protons.
that are moving about
frantically in shells.
two types of charge: PLUS and MINUS.
AND these RULES apply to charges:
with protons
to explore static electricity,
from sparking sparks
to making your hair stand on end,
static electricity does not supply
stable electrical power.
To get BEYOND the mere parlor tricks
of static electricity,
people had to figure out HOW to generate
a more reliable source
of electricity than just sparks.
To do that, they first figured out
how to build a battery.
electronics became possible.
People discovered not only
electrical CHARGE,
but also learned
to define and measure
the key electrical quantities. . .
Current!
Resistance!
positive and negative charges
to understand electricity
or, for that matter,
to correctly install batteries.
scientists discovered that there are
two types of charges in our universe:
positive and negative.
in your kit.
that measures all three of these: voltage, current, resistance!
Let’s charge forward and measure VOLTAGE!
screen
around your home.
and rechargeable
batteries (optional)
to 20 DCV
(Direct Current Voltage).
and black
test leads,
as shown.
will appear
on the LCD screen
of the multimeter.
to the positive terminal
and the black probe
to the negative terminal
of each NEW battery
to measure its voltage.
in STEP 3 in your book
or on a sheet of paper.
to turn OFF the meter
when you are finished.
Use your observations
to answer the question
on the next slide.
a used battery different from a new battery
negative charge in a wire
of an alkaline AA cell battery