(_12)+Electrical+Circuits

PAGE EDITOR(S): Fabi Praca, Dorothy Kafka, Alex Haubold, Dan Trauner

**Natland Note: (08/08/10):** Only you can prevent forest fires! <= Dan Trauner you are silly man.

Basic Class Notes:

Other Examples from class:



In the real world, circuit diagrams can get fairly complicated: [] For our purposes, the AP only covers resistors and capacitors, and only deals with combinations of series and parallel wiring.

Here are some notes from Physics Classroom and some practice problems that are very helpful. Enjoy.

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Schematic Symbols
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=**High Voltage Jell-O **= media type="youtube" key="yNIi1W87wrc" height="385" width="480"

__**Tree Branch on Power Lines**__
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[[image:clown.jpg]]
Clown Seal of Disapproval

media type="youtube" key="5S7DHiuIvbI" height="385" width="480" Why does the resistor catch fire?

(Ohm's Law)

V = 120V R = 47 Ω

I = (120/47) = ~2.55A of current

and P = (120^2)/47 = ~306W

That 47 Ω resistor isn't designed to handle that high of a voltage/current (it would normally be used within smaller circuits in various electronic devices). The large amount of excess energy dissipated over the resistor was dissipated in the form of extreme heat, causing it to catch fire.

Inside a surge protector, like the clown above used, one would find a circuit looking something like this:



Each "outlet" on the surge protector is wired in __parallel__, so each component in the circuit receives the same 120V AC (USA) from the wall socket. At the same time, there is a fuse somewhere in the green area (a small section of wire designed to purposely overheat and break the circuit) connected in __series__ with the rest of the "outlets". If a current greater than what the fuse can handle is present, the fuse is broken, and therefore the flow of charges to the (often expensive) electronic devices connected to it stops (and this prevents damage due to "electrical surges").

(Solutions Available on College Board Website)
 * __Two Circuits AP Problems__**

media type="youtube" key="70gh5GrX4xI" height="525" width="660" How to make a cool lemon battery. This is way better then Natty's bananalarm. I mean seriously it is...

media type="youtube" key="FwEz9ygPHiM" height="405" width="500" Ohm's Law, thoroughly explained.

media type="youtube" key="jWxPl4izlas" height="405" width="500"  This video clearly explains the importance of electricity in our world. The "electric avenue" is a more common form of an electric circuit. The "avenue" being the wire through which the charges can freely flow (current).  If you listen closely (or read the lyrics) you will realize that one of the most classic songs of all times, is actually just talking physics. For instance "Now in the street there is violence" is clearly referring to resistors that are restricting the flow of current in a circuit. The battery therefore has "lots of work to be done." Try to get all you can from this video. It's more for the audio learner. A new approach to the physical concepts of life.

 media type="youtube" key="2i8qT9M3ECA" height="364" width="445"  Fun with high voltages. Do not try this at home, especially you Mr. Paul Natland

 media type="youtube" key="hvS6bOKLhFs" height="364" width="445"  Best way to cook a hot dog.


 * __SOURCES__**

Clown Seal of Disapproval Created using various images, and some Photoshopping by Dan

Inside a Surge Protector Image []

Title Image [|****http://www.ngfl-cymru.org.uk/vtc/Phase3delivery/Wales/Science/Keystage1/Physicalprocess/Electricalcircu/Introduction/circuits.gif****]

Stupidly Complex Circuit Diagram [|******http://www.fmtunerinfo.com/CT-7000schematic.jpg******]

College Board AP Physics B Free Response Questions and Solutions []

Great site for review sheets for ALL topics []

Source for Resistor Burning Video [|****http://www.youtube.com/watch?v=5S7DHiuIvbI****]

Source for Lemon Circuit Video http://www.youtube.com/watch?v=70gh5GrX4xI

Source for Ohm's Law Video http://www.youtube.com/watch?v=FwEz9ygPHiM

Source for Hot Dog cooking http://www.youtube.com/watch?v=hvS6bOKLhFs&feature=related

Fun with High voltages video http://www.youtube.com/watch?v=2i8qT9M3ECA

Source for Electric Avenue video http://www.youtube.com/watch?v=jWxPl4izlas

Source for Ohm's Law Explanation http://www.youtube.com/watch?v=FwEz9ygPHiM

Source for Tree Branch Video [|http://www.youtube.com/watch?v=g4ph-h7l_aM]