# Electricity stuff

# Formulas

### Current (I) (amps)

<table border="1" id="bkmrk-parallel-it-%3D-i1-%2B-i" style="border-collapse: collapse; width: 100%;"><colgroup><col style="width: 50%;"></col><col style="width: 50%;"></col></colgroup><tbody><tr><td>Parallel</td><td>I<sub>T</sub> = I<sub>1</sub> + I<sub>2</sub> + I<sub>3</sub></td></tr><tr><td>Ohms law

</td><td>I = V/Ω

</td></tr><tr><td>Individual current of resistor (Series)</td><td>I<sub>T</sub> = I<sub>1</sub> = I<sub>2</sub> = I<sub>3</sub>

</td></tr><tr><td>Individual current of resistor (Parallel)</td><td>(Total resistance / individual resistance) x total circuit current

</td></tr></tbody></table>

### Voltage (V) (Volts)

<table border="1" id="bkmrk-voltage-drop-across-" style="border-collapse: collapse; width: 100%;"><colgroup><col style="width: 50%;"></col><col style="width: 50%;"></col></colgroup><tbody><tr><td>Voltage drop across each resistor</td><td>V = I x R</td></tr><tr><td>Voltage across resistros in a circuit (Parallel)</td><td>V<sub>T</sub> = V<sub>1</sub> = V<sub>2</sub></td></tr></tbody></table>

### Power (W) (Watts)

<table border="1" id="bkmrk-power-dissipated-by-" style="border-collapse: collapse; width: 100%; height: 59.5938px;"><colgroup><col style="width: 50%;"></col><col style="width: 50%;"></col></colgroup><tbody><tr style="height: 29.7969px;"><td style="height: 29.7969px;">Power dissipated by a resistor</td><td style="height: 29.7969px;">P = I x V</td></tr><tr style="height: 29.7969px;"><td style="height: 29.7969px;">Power dissipated by a resistor</td><td style="height: 29.7969px;">P = I<sup>2 </sup>x Ω</td></tr><tr><td>Power dissipated by a resistor</td><td>P = V<sup>2</sup> / Ω</td></tr></tbody></table>

### Resistance (Ω) (Ohms)

<table border="1" id="bkmrk-resistance-with-mult" style="border-collapse: collapse; width: 100%;"><colgroup><col style="width: 50%;"></col><col style="width: 50%;"></col></colgroup><tbody><tr><td>Resistance with multiple resistors (Parallel)</td><td>Ω = (R<sub>1</sub><sup>-1 </sup>+ R<sub>2</sub><sup>-1 </sup>+ R<sub>3</sub><sup>-1</sup>) <sup>-1</sup></td></tr><tr><td>Resistance with multiple resistors (Seiries)</td><td>Ω = R<sub>1</sub> + R<sub>2</sub> + R<sub>3</sub></td></tr><tr><td>Ohms law</td><td>Ω = V / I</td></tr><tr><td>Resistivity</td><td>resistivity x length (m) / cross sectional area</td></tr><tr><td>Resistance at certain temprature</td><td>Resistor 1 resitance x (1 + resistance at temprature x (temp 1 - temp 2)</td></tr></tbody></table>

### Time constant (τ) (Tou)

<table border="1" id="bkmrk-1-time-constant-%CF%84-%3D-" style="border-collapse: collapse; width: 100%;"><colgroup><col style="width: 50%;"></col><col style="width: 50%;"></col></colgroup><tbody><tr><td>1 time constant</td><td>τ = Capacitance x Resistance</td></tr><tr><td>  
</td><td>  
</td></tr></tbody></table>