Electricity and Introduction to Circuits and Static Electricity

1. Electricity and Circuits
Physical Science
Mrs. Neistadt

2. *Electricity
• *What is electricity?
*Electricity is a general term for anything that involves an electrical charge.
• *What causes an electrical charge?
*An electrical charge is caused by an imbalance in positive or negative
charges.

3. Electricity and Circuits
• *What is an electrical circuit?
• **An electric circuit is something that
provides a path through which
electricity travels.
• We use electrical circuits everyday in
all of our electrical appliances.
What exactly is electricity? How does it
work?

4. What is electricity?
• *Electricity usually means the flow of an
electric current in wires, motors, light bulbs,
and other devices.
• *Electricity is like water, except it flows
through solid metal so we can’t usually see it.
• *Just like water, electric current can travel
over great distances.

5. What are examples of an electric circuit?
• An electric circuit is something that provides a path
through which electricity travels.
*Some electric circuits exist in the natural world:
– *Nerves in your body create electric circuits
– *Lightning, clouds, and planet Earth form an electric circuit
*Some Man-made electric circuits are::
– *Wiring that lights your house
– *Car battery, ignition switch, and starter in a car

6. 1. The nervous
system in the
body acts like an
electric circuit.
A. Yes
B. No

7. 2. Which of these is NOT
an electric circuit?
A. The wiring the lights your
house.
B. Lightning, clouds, planet Earth
C. Water flowing through pipes
[Default] a house.
in
[MC Any]
[MC All]

8. Electric currents = water pipes
• Electric circuits are similar to pipes and hoses
for water.
– The big difference is that when you cut a hose, the
water flows out, but when you cut a wire,
electricity stops flowing.

9. *Two types of Circuits
• *Closed Circuits: current flows
• *Open circuits: no current flows
• *The most common problem in circuits is an
unintentional break in the circuit.

10. 3. When a current is
broken, where does
the electricity go?
A. It spills out onto the ground.
B. The current stops, electrical currents only
flow in closed circuits.
[Default]
[MC Any]
C. All] floats off into space.
[MC It

11. 4. An open circuit is a
circuit with no breaks in
it.
A. True
B. False

12. 5. A closed circuit
turns a light off.
A. True
B. False

13. Switches and Circuits
• *A complete path through wire is
needed for electricity to work.
• *A switch works by breaking or
completing the circuit path.
• *When the switch is on: the circuit path
is complete.
• *When the switch is off: the circuit path
is broken.

14. *Circuit diagrams make drawing circuits much
easier.

15. Closed Circuits = Electricity Flow

16. Open Circuit = No Flow

17. Circuit Diagram Symbols

18. Answer in your own words:
1. On your paper, create a drawing of an electric
circuit using the symbols found on page 109.
2. What is a closed circuit?
3. What is an open circuit?
4. If you compare an electrical circuit to a system that
carries water, what would the water pipes
represent?
Summarize:
Now that you’ve learned a little more about electrical
circuits, answer the original question again: What is
an electrical circuit? Answer in your own words.

19. Electricity and Circuits
Part II
Physical Science
Mrs. Neistadt

20. Bellwork Questions:
1. What is Static Electricity?
2. When have you experienced static
electricity?
**Static Electricity- a build up of either positive
or negative charge; consists of isolated
motionless charges, like those produced by
friction.
Examples: brushing hair; cat fur; socks on
carpet; clothes from the dryer…

21. Review Questions:
1. If you compare an electrical circuit to a
system that carries water, what would the
water pipes represent?
2. Is a closed circuit on or off?
3. A circuit with the switch turned to the OFF
position or a circuit with any break is called
an open or closed circuit?

22. History
• The study and using of electricity is relatively
new: scientists only began understanding
electricity in the late 1800s.
• Scientists first believed electricity was caused
by two fluids in an object.
• They now know that it is not fluid, but positive
and negative charges of an electrical energy in
an object.

23. More history
• *Electric charge is a fundamental property of
matter that comes in two forms.
• *Benjamin Franklin was one of the
scientists who discovered this fact.
• *Ben Franklin also named the two forms of
charges positive and negative.

24. Static Cling Anyone?
• If objects can have a positive or a
negative charge, what happens
when there is a buildup of these
charges?
• *When an object carries extra
positive or negative charges, we
say it is electrically charged.

25. 6. Benjamin Franklin
thought electricity
was caused by a
certain fluid present
in an object.
A. True
B. False

27. Charges
• *Like charges (+,+) (-,-) repel each other
• *Unlike charges (+,-) attract
• *An object that has equal positive and
negative charges is called: electrically neutral
• *This property of matter, Charge, gives rise to
both electricity and magnetism.

29. Practice Questions:
1. Positive electric charges:
a. attract both positive charges and negative charges
b. Repel both positive charges and negative charges
c. Attract positive charges and repel negative charges
d. Repel positive charges and attract negative charges
2. Electric charge is:
a. Caused by two fluids, as described by Benjamin Franklin
b. Present in metals only
c. A fundamental property of matter that comes in two forms
d. Found only in non-living material

30. What is happening in the picture?
This picture was taken after the girl had rubbed the balloons over her hair and then pulled them away.
An atom contains protons at the center and electrons which surround it on the outside. The number of
protons in an atom can't change, but electrons can either be added or taken away. This causes the
atom to have a positive or negative charge. In this case, electrons were transferred from the balloon
to her hair, giving the balloon a positive charge and her hair a negative charge. This is due to the
Conservation of Electric Charge, which says that electric charge can't be created or destroyed. Since
positive and negative charges attract, her hair is attracted to the balloon and sticks to it.

31. Balloon Questions
Answer on your paper:
1. How did the balloons get stuck to the board?
2. What did rubbing do to the balloons?
3. Why do you think balloons will stick better
on a very cold winter day than on a rainy
day?
4. Can the balloons stick to the walls forever?

32. Answer on your paper:
• Complete Concept Review Questions
• #1-11 on page 115 of your text
• Please turn in