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.

Schematic Symbols

High Voltage Jell-O

Tree Branch on Power Lines

47Ω Resistor vs. 120V AC Wall Socket


Clown Seal of Disapproval

Why does the resistor catch fire?

(Ohm's Law)

V = 120V
R = 47

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

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").

Two Circuits AP Problems
(Solutions Available on College Board Website)

How to make a cool lemon battery. This is way better then Natty's bananalarm. I mean seriously it is...

Ohm's Law, thoroughly explained.

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.

Fun with high voltages. Do not try this at home, especially you Mr. Paul Natland

Best way to cook a hot dog.


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

Inside a Surge Protector Image

Title Image

Stupidly Complex Circuit Diagram

College Board AP Physics B Free Response Questions and Solutions

Great site for review sheets for ALL topics

Source for Resistor Burning Video

Source for Lemon Circuit Video

Source for Ohm's Law Video

Source for Hot Dog cooking

Fun with High voltages video

Source for Electric Avenue video

Source for Ohm's Law Explanation

Source for Tree Branch Video