Transcript Electricity PowerPoint

Electricity
SOL 4.3
(Information used from www.solpass.org)
Currents and Circuits
 A continuous flow of negative charges
(electrons) is a current.
 The pathway taken by an electric current
is a circuit. Closed circuits allow the
movement of electrical energy. Open
circuits prevent the movement of
electrical energy.
Circuits
 Open Circuit
 Closed Circuit
 Lights off
 Lights on
Series and Parallel
Circuits
 There is only one
pathway for the
current in a series
circuit.
 In a parallel circuit,
there are two or
more pathways for
the current.
Conductors
 Help electrical energy move better
 Good conductors: metals and water
Insulators
 Do not help electrical energy move
through materials
 Can be used to reduce heat produced by
friction
 Good insulators: rubber, plastic, wood
Static Electricity
 Rubbing certain materials
together can create static
electricity. (rubbing your shoes
repeatedly on carpet and then
shocking your friend when you
touch them!)
 Lightning is the discharge of
static electricity in the
atmosphere.
Electrical Energy
 Can be transformed into heat, light or
mechanical energy
 An electric current creates a magnetic field,
and a moving magnetic field creates an electric
current. This current can produce electrical
energy.
 Benjamin Franklin learned that lightning was a
form of electricity.
 Thomas Edison invented the light bulb.
 Michael Faraday invented batteries.
Electromagnets
 Created by a current flowing
through a wire
 Wrapping a wire around an
iron nail and then connecting
the ends with a battery is an
example of a simple
electromagnet. They are very
useful because you can turn
them on and off.
Quiz Time #1
 Which will light a light bulb?




A.
B.
C.
D.
An open circuit
A closed circuit
Both A and B
Neither A nor B
Correct Answer-B
Quiz Time #2
 If you have a string of holiday lights on your
tree and they go dark when one little bulb
burns out, the string of lights is a . . .




A.
B.
C.
D.
Series Circuit
Parallel Circuit
Conductor
Insulator
Correct Answer-A
Quiz Time #3
 If you have a set of lights
where one bulb burns out
but the others remain lit, it
is a . . .




A.
B.
C.
D.
Series circuit
Parallel circuit
Conductor
Insulator
Correct Answer-B
Quiz Time #4
 Electrical energy moves easily through
materials that are good conductors.
Which one of these is the best
conductor?




A.
B.
C.
D.
Wood
Rubber
Cloth
Metal
Correct Answer-D
Quiz Time #5
 You are working on an experiment and your
wires keep overheating and stopping your
work. What insulator could you use to help
solve this problem?




A.
B.
C.
D.
Rubber
Copper
Iron
Nickel
Correct Answer-A
Quiz Time #6
 This is a dry-cell
battery. Who is
credited for inventing
batteries?




A.
B.
C.
D.
Benjamin Franklin
Franklin Roosevelt
Michael Faraday
Thomas Edison
Correct Answer-C