Ch. 24: Electric Current and Circuits

1
Ch. 24 Electric Current and Circuits

• Vocabulary
• electrical energy, electric current, circuit,
  closed circuit, conductor, closed circuit

2
Electric Circuits

• All electric circuits come in two basic flavors.
• They are either open or closed.
• Closed circuits are completely connected, and the
  electricity can flow.
• Open circuits have a spot or spots where they are
  not connected and will not allow electricity to
  flow.

3
Closed Circuits

• In a circuit we talk about the flow of
  electricity, it is called electric current.
• In the simple closed circuit from before the
  electricity flows out of the top section of the
  battery (positive end), through the wire, into
  the light bulb (making it light up), then into
  the next wire, and back into the bottom of the
  battery (negative end).
• If everything stay connected (closed) then the
  electricity will continue to flow.
• We use wires to carry electric current because
  they are good conductors.
• Conductors are materials that allow electricity
  to flow through them.
• Wires are usually made out of copper, because
  copper is an excellent conductor.

4
Open Circuits

• Open circuits do not allow electricity to flow.
• When a hole happens in the circuit, then the
  circuit opens and the electricity cannot flow
  back into the battery and the whole operation
  shuts down.
• This is not always a bad thing.
• Sometimes you dont want a circuit to be closed
  all the time, like on a lamp, you want to be able
  to sleep sometime.
• A device called a switch can be placed inside the
  circuit that will open or close the circuit
  whenever you want.

5
Open Switch vs. Closed Switch
6
Electricity?

• The appliances in your house are too large to run
  on batteries.
• Instead the electricity is produced in a power
  plant and sent through wires into your house,
  powering everything that needs electricity where
  you live.
• REMEMBER! Electricity does not come from wires,
  it only travels through them.

7
Questions About Chapter 24

1. Why are switches installed into electric
   circuits?
2. Name two places that electricity comes from.
3. What are the two basic types of electric
   circuits?
4. What is electric current?
5. Draw a picture of a simple closed circuit.
   Include wire, a battery, and a light bulb.