2. Outline
of
the
Presenta6on
I. Charges
II. Current
III. Voltage
3. What
are
charges?
An
atom
with
one
or
more
electrons
missing
becomes
charged.
Two
Types
of
Charges:
Posi6ve
Charge-‐
protons
exceeds
the
number
of
electrons
(+)
Ex.
Na+
Nega6vely
Charge-‐electrons
exceeds
the
number
of
electrons.(-‐)
Cl-‐
4.
5. Electrical
Forces
and
Charges
The
fundamental
rule
at
the
base
of
all
electrical
phenomena
is
that
like
charges
repel
and
opposite
charges
a9ract.
6. How
charges
are
transferred?
When
electrons
are
transferred
from
the
fur
to
the
rod,
the
rod
becomes
nega6vely
charged.
8. Principle
of
Conserva=on
of
Charge
Electrons
are
neither
created
nor
destroyed
but
are
simply
transferred
from
one
material
to
another.
9. What
is
a
Current?
Current
is
the
movement
of
charges
in
a
circuit
Electric
current
is
measured
in
amperes,
symbol
A.
An
ampere
is
the
flow
of
one
coulomb
of
charge
per
second.
When
the
flow
of
charge
past
any
cross
sec6on
is
1
coulomb
(6.24
billion
billion
electrons)
per
second,
the
current
is
1
ampere
10. What
is
Voltage
Voltage
provides
the
energy
to
move
the
charges.(electrons)
Important:
charges
cannot
move
in
a
circuit
without
poten6al
difference
across
11. Voltage
Source
Power
u6li6es
use
electric
generators
to
provide
the
120
volts
delivered
to
home
outlets
This
means
that
120
joules
of
energy
is
supplied
to
each
coulomb
of
charge
that
is
made
to
flow
in
the
circuit.
A
baVery
is
another
source
of
voltage.
It
provide
varying
amounts
depending
on
its
nature
and
size.