Post on 11-May-2015
description
Electricity
SNC1D0
What is electricity?
Electricity is the energy generated from the transfer of electrons
Electrons are located on the outside of atoms, and can easily move in or out of atoms
Electric Charges
When objects have no loss or gain of electrons, they can be considered “neutral”
When an object gains electrons, it becomes “negatively” charged
When an object loses electrons, it becomes “positively” charged
Law of Electric Charges“Like charges repel one another, and unlike
charges attract one another.” An object with opposite charges will attract each
other A charged object and a neutral object will attract
each other Same charged objects repel each other Neutral objects have no effect on each other
Types of Electricity
There are 2 main forms of electricity
Static electricity refers to when electrons are built up on an object
Current electricity refers to a flow of electrons
Conductors and Insulators
Conductors are materials that allow electrons to flow freely through them (metals)
Insulators are materials that do not allow easy flow of electrons (rubber, plastics)
Static Electricity
Static electricity can be generated through a variety of ways:
Friction - electrons rub onto another object
Contact - electrons jump onto another object
Electrostatics Electrostatics refers to
the ability for something to hold onto electrons, the study of static electricity
Something with a greater hold on electrons can “steal” electrons from something with a weaker hold
(Weak hold of electrons)
Acetate
Glass
Wool
Cat fur, human hair
Calcium, magnesium, lead
Silk
Aluminum, zinc
Cotton
Parafin wax
Ebonite
Plastic
Carbon, copper, nickel
Rubber
Sulphur
Platinum, gold
(strong hold on electrons)
Electrostatics Example: If you rub a glass rod
with a piece of silk, the electrons go to the silk from the glass
The silk becomes negatively charged
The glass becomes positively charged
(Weak hold of electrons)
Acetate
Glass
Wool
Cat fur, human hair
Calcium, magnesium, lead
Silk
Aluminum, zinc
Cotton
Parafin wax
Ebonite
Plastic
Carbon, copper, nickel
Rubber
Sulphur
Platinum, gold
(strong hold on electrons)
Charging by Contact
When a charged object touches a neutral object, it becomes charged as well
Example: When you touch a charged sphere, the electrons jump into your body and charge your hair
Method of Creating Static ChargesMethod ofCharging
InitialCharge onObjects
Amount ofContactBetweenObjects
Final Chargeon Objects
ElectronMovement
Friction Bothobjects areneutral
Lots ofcontact (themore contactthe greaterthe charge)
Oppositecharges (onepositive, onenegative)
Move from objectwith weak hold onelectrons to objectwith strong holdon electrons
Contact One neutralobject
Onechargedobject
Brief touch(no rubbing)
Sometimesno contactwhichcreateselectricalshock
Both havesame charge
Attempt tobalance chargeon originallycharged object
Current Electricity
Current electricity refers to a flow of electrons
A continuous source of electrons flow from one place to another