I.                    Chapter 13  Electricity and Magnetism

A.     Static Electricity

1.                  Static Electricity is caused when positive and negative
      charges are no longer balanced.

a)                  Atoms are the tiny building blocks that everything is made of.

b)                  Atoms have 3 different particles.

(1)               Some have a positive charge (+) Protons

(2)               Some have are neutral because they have
      no charge (Neutrons)

(3)               Unlike charges attract each other (+) & (-)

(4)               Like charges repel each other (+) & (+) or (-) & (-)

2.                  The space around a charged item is called an electric field.

a)                  The electric field causes an electric force.

b)                  A positive electric field attracts negative charges.

c)                  A negative electric field attracts positive charges.

3.                  Lightning is caused by static electricity.

a)                  Charged particles move between atoms in storm clouds.

b)                  The positive particles cluster near the top.

c)                  The negative particles gather near the bottom.

B.     Current Electricity

1.                  Current Electricity is when electric charges flow from one
      place to another through wires.

2.                  The flow of electric charges is not the same in all materials.

a)                  Conductors allow electric charges to pass through easily

(1)               Silver is an excellent conductor, too expensive.

(2)               Cooper is used for wires in the home because it is
            also a good conductor.

(3)        Aluminum is used for outside power lines because it is
            stronger and lighter.

(4)               Most metals are conductors.

b)                  Insulators make it more difficult for electric charges
       to pass through.

(1)               plastic

(2)               rubber

(3)               glass

(4)               dry wood

(5)               Wires are covered with insulation to keep electric
      charges from coming in contact with other wires.

3.                  Resistance means the material does not allow electric charges
      to flow through easily.

4.                  Electricity will only flow through a closed circuit.

5.                  Two types of circuits

a)                  Series Circuit

(1)               Charged particles travel in one direction
      along a single path.

(2)               All bulbs along the path receive the same
      amount of electricity.

(3)               When one bulb burns out all the bulbs go out.

(4)               Today people rarely use series circuits.

b)                  Parallel Circuit

(1)               It connects several light bulbs in a way that each
     has its own path to the power source.

(2)               Circuits in our homes, schools, and other
      buildings are parallel circuits.

(3)               One burned out bulb does not cause the others
      to go out.

(4)               It can also handle electrical devices that need
     different amounts of current.

C.     Magnetism

1.                  A magnet is anything that attracts other things made of
      iron, steel, and certain other metals.

2.                  Magnetism is the force around a magnet.

3.                  Magnets have 2 poles

a)                  A north-seeking pole

b)                  A south-seeking pole

4.                  Magnets are strongest at their poles.

5.                  Like poles N-N, S-S push away or repel.

6.                  Unlike pole N-S, S-N attract each other.

7.                  If you break a magnet in two, you will have 2 magnets.

a)                  Each will have a north-seeking pole and
     a south-seeking pole.

b)                  One cannot exist without the other.

8.                  A magnetic field is an invisible field around a magnet where
      magnetism acts.

9.                  The Earth is the largest magnet in the world.

a)                  The Earth has a north magnetic pole and a south
      magnetic pole.

b)                  A magnetic field surrounds the Earth.

c)                  A compass is a magnet that swings freely.

(1)               The compass needle reacts to the Earth’s
      magnetic poles.

(2)               used to find direction

D.     Electricity is transformed to magnetism.

1.                  An electromagnet is a coil of wire with loops wrapped around a
      piece of iron through which an electric current passes.

a)                  It is a very strong magnet.

b)                  You can turn it off by turning off the current.

c)                  You can make it stronger

(1)               increase the amount of current

(2)               using more turns of the coil

(3)               using a larger piece of iron

d)                  Uses

(1)               Lift heavy materials

(2)               Televisions

(3)               DVD players

(4)               Motors

(5)               Doorbells

(a)                Electromagnets convert electric energy to
      magnetic energy to mechanical energy.

E.      Magnetism Transformed to Electricity

1.                  Michael Faraday

a)                  He discovered that changing a magnetic field
      created an electric current in a wire.

b)                  He shared his discovery with other scientists.

c)                  He built the first electric motor.

2.                  Generators are machines that create electric energy by
      turning coils of wire around powerful magnets.

a)                  The basic idea is the same as Mr. Faraday’s.

b)                  It uses magnets and wires to turn mechanical energy into
      electrical energy.

c)                  Energy is needed to spin the wires around magnets.

(1)               Sources of energy

(a)                Wind

(b)               Water

(c)                Steam

(d)               Nuclear