1. Learning Objectives I can describe the parts of an electric circuit.
I can distinguish between open & closed circuits.
I can distinguish between a series circuit and a parallel circuit.
I can describe safety precautions people should use in lightning storms and operating appliances.

2. Ohio New Learning Standards for Science
Ohio 7th Grade, Physical Science #3 (7.PS.3) – Energy can be transferred through a variety of ways.

3. Lesson Opener

4. Unit 8, Lesson 6 – Electric Circuits
What are the parts of an electric circuit?
- an electric circuit is a complete, closed path through which electric charges can flow
- all electric circuits contain three basic parts: an energy source, an electrical conductor, & a load
- the energy source converts some type of energy, such as chemical energy, into electrical energy

5. Unit 8, Lesson 6 – Electric Circuits
- examples of energy sources could be a battery, solar panels, wind turbines, and nuclear power plants

6. Unit 8, Lesson 6 – Electric Circuits
- the materials in which electric charges can move easily are called electrical conductors
- copper wire is a fantastic conductor!
- most conductors are covered with insulators to prevent electrical shock

7. Unit 8, Lesson 6 – Electric Circuits
- lastly, all circuits have a load, which is a device (light bulb, computer, flat screen, fan, etc…) that uses electrical energy to operate
Complete #7, pg.601

8. Unit 8, Lesson 6 – Electric Circuits
1. cd player
2. digital clock
3. cell phone
4. computer
5. fan
6. lamp
7. electric bass guitar

9. Unit 8, Lesson 6 – Electric Circuits
How are electric circuits modeled?
- to make an electric circuit, you only need three basic parts: an energy source, an electrical conductor, and a load
- since most circuits have more than one load, circuit diagrams are often used to display their arrangement for engineers and electricians

10. Unit 8, Lesson 6 – Electric Circuits
a wire is shown as a line
the load is represented by a zigzag line
parallel lines show the energy source
two open circles is an open switch
two closed circles is a closed switch

11. Unit 8, Lesson 6 – Electric Circuits
How does current stop and start?
- electric charges move continuously in the closed loop of an electric circuit
- opening a switch stops the charges from moving, but closing the switch creates a closed loop, allowing the charges to flow
Complete #9, pg.603

12. Unit 8, Lesson 6 – Electric Circuits

13. Unit 8, Lesson 6 – Electric Circuits
Complete #10, pg.603

14. Unit 8, Lesson 6 – Electric Circuits
How do series circuits & parallel circuits differ?
- simple electric circuits that contain one energy source & more than one load are classified as either a series circuit or a parallel circuit
- in a series circuit, all parts are connected in a row that forms one path for the charges to follow
- the current will be the same for all loads in a series circuit but if one of the loads fails, they all fail!

15. Unit 8, Lesson 6 – Electric Circuits

16. Unit 8, Lesson 6 – Electric Circuits
- in a parallel circuit, electric charges have more than one path that they can follow
- loads in a parallel circuit are connected side by side, so if one of them fails, the rest will still work!
- the current in a parallel circuit can be different for all the loads, but they all receive the same voltage
What circuit would be best for Christmas lights?
Answer: Parallel Circuit!

17. Unit 8, Lesson 6 – Electric Circuits

18. Unit 8, Lesson 6 – Electric Circuits
Complete #12, pgs.604 & 605

19. Unit 8, Lesson 6 – Electric Circuits
Complete #12, pgs.604 & 605

20. What is an electrical circuit?
What Are Circuits Worksheet accompanies this slide.

21. Unit 8, Lesson 6 – Electric Circuits
How can I use electricity safely?
- stay away from places where there is high-voltage electrical equipment & avoid using electrical equipment/appliances near water!!!!

22. Unit 8, Lesson 6 – Electric Circuits
- be aware of your surroundings at all times! People have been electrocuted in swimming pools due to electrified water from broken lights
Rachel Rosoff (17) died in 2016

23. Unit 8, Lesson 6 – Electric Circuits
- damage to wires can cause a “short circuit,” in which charges do not pass through all the loads (current increases and wires can get hot enough to start fires)
- fuses, circuit breakers, & ground fault circuit interrupters (GFCIs) are safety devices that act like switches to turn off current

24. Unit 8, Lesson 6 – Electric Circuits
- when lightning strikes, electric charges can travel between a cloud and the ground
- lightning usually strikes taller objects, so stay away from trees, monuments, and tops of buildings
- most of the taller buildings & monuments have lightning rods, which provide direct paths to the ground for the electrical charges to flow!

25. Unit 8, Lesson 6 – Electric Circuits
Lightning striking a tree in Kansas

26. Unit 8, Lesson 6 – Electric Circuits
Lightning striking the “Christ the Redeemer” monument in Rio de Janeiro, Brazil

27. Unit 8, Lesson 6 – Electric Circuits
Lightning striking downtown Dallas, Texas

28. Unit 8, Lesson 6 – Electric Circuits
Lightning striking the Burj Khalifa in downtown Dubai, United Arab Emirates (U.A.E.)

29. Visual Summary

30. Exit Question
How does a lightning rod protect a building from lightning damage?