# What is electricity

Electricity is the flow of electric charge.

# Atoms

Atoms are build up of Protons, Neutrons and Electron.

Electrons can escape the atom and bind to a new Atom.

Copper is used in wires because it has 29 Electrons, with one in the outer (Valence) Shell. This Atom can easily escape and switch places.


## Ohms Law

V = I * R;

I = V / R;

## Voltage
is like the pressure in Cable, it forces the Electrons to move.

## Current
A cable with a lot of electrons flowing through it has a high current.
A cable can only handle a specific type of current.
When the current is to high, the cable breaks

## Circuit
A electric circuit is a closed loop through which electrons flow.

## How to find resistance of resistors in series?
Just add them up

## How to find the resistance of resistors in parallel?

When each of the resistors provides a new way to reach ground, then 

1/R = 1/R1 + 1/R2 + 1/R3;

**Example:**

R1 = 4 Ohm
R2 = 5 Ohm
R3 = 20 Ohm

1/R = 1/4 + 1/5 + 1/20;
1/R = 0.5 | * R;
1 = 0.5R  | * 2;
2 = R;

10 Ohm
23 Ohm
17 Ohm

1/R = 0.20230179 | * R
1 = 0.20230179R  | / 0.20230179
4.94 = R;

## Test

Input: 50v
Current: 2A
Resistors: 19Ohm

Ohms Law = V = I*R;
50 = 2*(19+R);
50 = 38+2R      | - 38;
12 = 2R;
6  = R;

R = V / I;

Ohms law only works for D/C and NOT A/C;

5V in 

1/R = 1/100+1/1000;
1/R = 0.011;
1 = 0.011R;
90.90909 = R;

I = V / R; 
I = 5 / 90.909090
I = 0.055;
I = 5.5mA



## Watts
## Volts
## Amps