# Resistance and Ohms

**Resistance** is opposition to current, is measured in Ohms ($Ω$), and defined by Ohm's Law as voltage over current, or $R = V/I$. The inverse of resistance is conductance.

**Resistors** are materials that resist the flow of electricity, and therefore have a high resistance (and thus a low conductance) value, hence the term "resistor" for the electrical component which reduce current.

## History

The term "ohm" is named after Georg Simon Ohm, who first derived the relationships between current, voltage, and resistance now known as Ohm's Law.

## Deeper Knowledge on Resistance and Ohms

### Conductance and Siemens

The ability to conduct to current, measured in siemens

### Resistors (Electrical Component)

Electrical components that resist the flow of electricity

### Ohm's Law

A formula for determining voltage, current, and resistance

## Broader Topics Related to Resistance and Ohms

### Conductance and Siemens

The ability to conduct to current, measured in siemens

### International System of Units (SI)

Formal terms and definitions of the metric system

### Current and Amperes

The flow of electricity, measured in amps

### Voltage and Volts

Electrical potential energy, measured in volts

### Electricity

Energy that results from charged particles