Current Electricity
http://www.bing.com/videos/search?q=Bill+Nye%3a+Current+Electricity&FORM=HDRSC3#view=detail&mid=0AE4B02BBE26ECAD673
50AE4B02BBE26ECAD6735 (20 min)
• Electric current is a flow
of electric charge.
• Electrons moving in a
conductor such as a
copper wire.
• Ions through an electrolyte
• Battery or salt solution
CONDUCTORS AND
INSULATORS
• Conductors allow electrons to
flow through them easily.
Cu
• Copper atom has one valence
electron.
• Valence electrons of conductors
can gain enough energy to break
away and become free
electrons.
• Free electrons can move from
one atom to another. http://www.ndted.org/EducationResources/HighSchool/Electricit
y/valenceshell.htm
CONDUCTORS AND
INSULATORS
• Insulators do not allow
electrons to flow through
them easily.
• They are materials that do
not have any free electrons.
• They do not make good
conductors of electrical
currents.
• Ex wood, plastic, rubber,
noble gases
• Insulators
can protect
us from
electric
shock
Electric Circuit:
• A continuous path in which electric
current will flow.
• Example: current flowing from the power
source, through a copper wire to a light
bulb, and back to the power source.
• Batteries have many electrons at one end
(-ve) and few at the other (+ve).
• The electrons want to balance this charge
but they need a conductive path for them
to travel through.
Electric Circuit:
• If the (+ve) & (-ve) sides of the battery are
connected by a conductor, electrical current will
flow as the electrons move from the (-ve) side to
the (+ve )side.
(+)
(-)
Components of a Simple
Circuit:
• (ie: a battery)
• Schematic Diagram
of a simple circuit:
2. Electrical load:
(copy table 4 on p606 into notes)
1. Source of electrical energy:
• Anything that converts
electrical energy to another
form of energy (ie: toaster
converts electrical energy to
heat)
3. Circuit control device:
• (ie: a switch, a timer)
4. Connectors:
• wires that connect the
components of a circuit together
CURRENT ELECTRICITY:
http://www.youtube.com/watch?v=5laTkjINHrg
(10 min)
(intro current, coulomb)
– Introducing Current Electricity:
–
–
–
–
–
Read page 507-509 Answer # 2-6 page 510
Electric Current:
Read page 556-557 Answer # 1-3 page 557
Potential Difference:
Read page 560-561 Answer # 2-4 page 561
Electric Current:
• Electric current (I) is the amount of electric
charge (Q) that pass a given point in a
conducting wire every second(t).
Q
I=
t
• I is measured in SI units called amperes (A).
• Q is measured in coulombs (C).
– A coulomb is the charge carried by 6.25 x 1018
electrons
• t is measured in seconds (s)
• An Ammeter: Is a device used to measure the
electric current.]
Potential Difference:
• Electric potential difference is the
difference in potential energy (E) per
unit charge (Q) at one point of the circuit
compared to another point in the circuit.
• SI Unit: Volt (V)
E
V=
Q
• A Voltmeter: Is a device used to measure
the electrical potential difference.
Potential Difference:
• POTENTIAL DIFFERENCE:
http://www.youtube.com/watch?v=F1p3fgbDnkY
• (10 min)
Https://www.youtube.com/watch?v=l8JS8BbrVOg
(4 min)