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--- electricity [2022/10/07 09:50] – [Direct Current (DC)] jhagstrand
+++ electricity [2023/01/11 08:11] (current) – external edit 127.0.0.1
@@ Line 497: / Line 497: @@
 N = Number of turns
 e = EMF
+flux -> change in flux -> EMF\\
+https://youtu.be/Y2XvIofbwpc
@@ Line 767: / Line 771: @@
 | north | red  | negative | Earth's south pole, antartic |
 | south | blue | positive | Earth's north pole, artic    |
+Electromagnet also has poles.\\
+Fleming's right-hand-rule.\\
+http://kitbook.com/electromagnet-poles/
+battery plus to solenoid, wrap clockwise, starting at south pole, \\
+https://www.youtube.com/watch?v=n63DAWvaHlk
+letter N is counter-clockwise arrow symbol\\
+look at the north pole of the magnet\\
+current will be going thru the coil counter-clockwise\\
+letter S is clockwise arrow symbol\\
+look at the south pole of the magnet\\
+current will be going thru the coil clockwise\\
 ===== Electricity =====
@@ Line 781: / Line 805: @@
 | Direct      | DC | positive - negative | continuous flow           | straight line | battery |
+great animations of magnetic fields
+https://www.youtube.com/c/Physicsandanimation
 ==== Direct Current (DC) ====
@@ Line 809: / Line 837: @@
 In this example, what is moving: the people, or the space?
+some of the excuses I have heard.
+  * Too hard to change now.  Like telling Americans to drive on the left, there would be chaos.
+  * It doesn't matter mathematically in circuit analysis.  (not true for batteries, transistors and diodes)
+  * There are two simultaneous and opposite circuits: the electrons flow from negative to positive, the positive charge flows from positive to negative.  (False)
+Ben Franklin is often blamed for the mixup, because he described positive and negative charges 50 years before the first battery, and 150 years before the electron was discovered.
 Animation of ice cream queue.
 Circuit drawings: battery, LED.  Two drawings, electron and "conventional".
-{{ ::queue_chair.mp4 | Electron Queue Analogy}}
+{{ ::queue_chair.mp4?loop | Electron Queue Analogy}}
@@ Line 820: / Line 855: @@
 second-finger gives direction of the current\\
 which current is this?  electron or conventional
+He decided that the glass rod being rubbed with silk would be a positive charge while the rubber and fur would be a negative charge. So, with that convention, by removing electrons, the glass rod became positively charged and by adding electrons, the rubber rod became negatively charged.
+  * 1752 Ben Franklin flew his kite in a storm and captured electricity from lighting.  He described positive and negative charges.
+    * Rubbing a glass rod with silk produces a positive charge.
+    * Rubbing rubber with fur produces a negative charge.
+  * 1800 Alessandro Volta invented the first battery, the voltaic pile. https://www.liquisearch.com/alessandro_volta/first_battery
+    * zinc: negative electrode
+    * copper: positive electrode
+    * saltwater: electrolite
+  * 1861 Maxwell presents his equations (right-hand thumb rule?)
+  * 1897 J.J. Thomson discovers the electron, described it as a negatively charged particle floating in a sea of positive charge, like plums in a pudding, the "plum pudding model"
+  * 1909 Rutherford discovers the nucleus in the gold foil experiments and develops the planetary model
+  * 1913 Niels Bohr discovers the specific energy levels of electrons in the atom
+  * 1940 US Navy begins training electronics engineers using the electron current.
+  * 1945 John Ambrose Fleming dies
+Battery\\
+two terminals marked + and -\\
+Is that true?  Does the - terminal really have a superfluence of electrons?
+annode, cathode
+chemical reactions:
+  * oxidation = loss of electrons
+  * reduction = gain of electrons
+anion - has gained an electron, negative charge
+cation - has lost an electron, positive charge
+cathode - reduction occurs,
+anode - oxidation occurs, anions give off electrons, negative charge
+species?
+electrons flow from anode to cathode, from oxidation half to reduction half
+inside the battery, electrons flow from positive to negative inside the battery
+outside the battery, from negative to positive
+flow is reversed by a battery charger, something with a bigger voltage
+, AAA, AA, C, D dry cell
+^ description    ^ anode (-)    ^ cathode (+)          ^ electrolyte                        ^
+| zinc-carbon    | zinc         | manganese            | ammonium chloride or zinc chloride |
+| alkaline       | zinc powder  | manganese dioxide    | potassium hydroxide (alkaline)     |
+| lithium-ion    | carbon, graphite | lithium metal    | aquaeous salts                     |
+| li-ion polymer | carbon, graphite | lithium cobalt oxide | polymer                        |
+| lead-acid      | lead dioxide | metallic lead        | sulfuric acid                      |
+The electrolyte helps transport ions between positive and negative electrodes.
 ==== Alternating Current (AC) ====
+===== Magnetic Field =====
+==== Calculate and Plot a Magnetic Field ====
+Numerical Error with Simulation...\\
+https://physics.stackexchange.com/questions/139479/numerical-error-with-simulation-of-electric-charge-in-homogeneous-magnetic-field
+Mathematical Model of Magnetic Field Lines\\
+https://spacemath.gsfc.nasa.gov/earth/9Page23.pdf