Transcript ElectricityCircuitsp..

Electric charge is a property
of matter.
Static charges are caused by the movement of
electrons, resulting in an imbalance of positive
and negative charges.
At first, a balloon and a glass rod
each have balanced, neutral charges.
Static charges are caused by the
movement of electrons, resulting in an
imbalance of positive and negative
charges.
When they touch, electrons move
from the rod to the balloon.
electric charge
A property that allows one object to exert a
force on another object without touching it.
Electric charge can be positive or negative:
positive charge is a property of the proton,
while negative charge is a property of the
electron.
electric field
An area surrounding a charged object, within
which the object can exert a force on another
object without touching it.
Bell Fun 1-6-12
• Explain what you observed in
procedure form when you rubbed a
balloon on your hair and placed it
on an object in the room.
• Static Electricity: Charges build up, but
do not flow. The buildup of electric charge in
an object caused by the uneven distribution
of charged particles.
3 Causes of static electricity:
1st Cause of Static Electricity
1. Friction: transfer of electrons from one
object to another by rubbing.
• Ex: clothes in a dryer/ rubbing balloon on
hair.
2nd Cause of static electricity
2. Conduction: the transfer of electrons by
direct contact.
• Ex: touching a car door or someone and
getting shocked!
3rd Cause of Static electricity
3. Induction: the movement of electrons to
one part of an object caused by the
electric field of another object. The buildup of a static charge in an object when the
object is close to, but not touching, a charged
object.
Behaviors of Conductors/Insulators
• Conductors: Electrons are loosely bound to
the atom and electrical currents move freely
through the wire.
• Copper, aluminum, silver and iron.
• Insulators: Electrons are bound tightly to
atom and do not flow easily.
• Rubber, glass, plastic, sand, wood.
electric potential
The amount of potential energy per unit charge
that a static charge or electric current has.
Electric potential is measured in volts, and is
often called voltage.
volt
The unit of measurement for electric potential,
which is equal to one joule per coulomb. The
number of volts of an electric charge equals
the charge’s voltage.
Resistance
The property of a material that determines how
easily a charge can move through it.
Resistance is measured in ohms.
ohm
The unit of measurement for electrical
resistance.
electric current
A continuous flow of electric charge, which is
measured in amperes.
Ampere
The unit of measurement of electric current,
which is equal to one coulomb per second.
The number of amps flowing through a circuit
equals the circuit’s amperage.
How is Electric Current Measured?
• Electric current is measured
in amperes, or amps.
• Ohm's law states that current equals voltage
divided by resistance.
• Current Voltage
Resistance
Easy for Ohm’s Formula
Grounding
The creation of a harmless, low-resistance
path—a ground—for electricity to follow.
Grounding is an important electrical safety
procedure.
Circuit – complete path through which
electric charges can flow.
1. circuit has a source of electrical
energy.
2. circuits have devices that are run by
electrical energy.
3. electric circuits are connected by
conducing wires and a switch.
electric cell
A device that produces electric current using
the chemical or physical properties of
different materials. A battery consists of two
or more cells linked together.
Flow of electrons,
energy source
Superconductors – materials that have no
resistance to electrical flow. NO LOSS OF
ENERGY occurs in a superconductor.
• Resistor: A resistor uses electrical
energy or “resists” the flow of charge in
an electrical circuit.
Light bulb, any electrical appliance.
• Series Circuit: Only one path for the
current to take.
• Pro: Simple and cheap to make
• Cons: 1. If one light goes out, they all do
• Lights become dimmer as you add more
bulbs (less current and more resistance!)
Parallel Circuit: Several paths for
the current to take.
Pro: Individual bulbs can be turned
on and off without affecting each
other.
Ex: Household circuits