# Electricity

Electricity is the form of energy (the ability to do work) that results from charged particles (electrons, protons). **Power** ($P$) from electricity is generated when potential electrical energy, referred to as voltage, is released so that it "flows" through a conductor as a current where it encounters resistance. This flow is mathematically described by Ohm's Law, and the amount of power generated is described by the Watt's Law.

## Relationships between Voltage, Current, Resistance, and Watts

Ohm's Law and Watt's Law describe the relationship between volts, amps, ohms and watts as $I = V/R$ and $P=IV$, respectively. These equations allow for substitutions: for example $I$ can be substituted with $V/R$ so that $P=(V/R)V$ or $P=V^2/R$.

## SI Units Used in Electricity

Name | Symbol | Measures | Definition |
---|---|---|---|

Ampere | $A$ | Current | ${C}/{s}$ |

Coulomb | $C$ | Charge | $A \cdot S$ |

Farad | $F$ | Capacitance | $C/V$ |

Henry | $H$ | Inductance | $Wb/A$ |

Hertz | $Hz$ | Frequency | $s^{-1}$ |

Ohm | $\Omega$ | Resistance | $V/A$ |

Siemens | $S$ | Conductance | $A/V$ |

Tesla | $T$ | Magnetic field strength | $Wb/m^2$ |

Volt | $V$ | Voltage | $W/A$ |

Watt | $W$ | Power | $J/s$ |

Weber | $Wb$ | Magnetic flux | $V \cdot s$ |

## Deeper Knowledge on Electricity

### Charge and Coulombs

How force is exerted in electromagnetic field, measured in coulombs

### Conductance and Siemens

The ability to conduct to current, measured in siemens

### Current and Amperes

The flow of electricity, measured in amps

### Electrical Engineering

Build and deconstruct electrically powered devices

### Ohm's Law

A formula for determining voltage, current, and resistance

### Resistance and Ohms

Opposition to current, measured in ohms

### Voltage and Volts

Electrical potential energy, measured in volts

### Watt's Law (Power Law)

A formula to define the relationship between power, voltage, and current (P=IV)

## Broader Topics Related to Electricity

### Physics

The fundamental nature and properties of matter, energy, and motion

### Power (Physics)

Energy that results from charged particles