# Ohm's Law

### Short Topical Videos

### Reference Material

- Horowitz & Hill,
*The Art of Electronics, 2nd Ed.*, Ch. 1

## Ohm’s Law

where is voltage, measured in Volts (), with typical values ranging from (into an oscilloscope) to (power lines, severe arcing danger); is current, measured in Amperes (), typical values ranging from (relatively safe for bench-top work) to (very dangerous); is resistance, measured in Ohms (), typical values ranging from (power resistors dissipating a lot of power) to (almost a no-connect).

## Resistor

*Symbol for a resistor in schematics*

A resistor resists the flow of electrons, such that a potential (i.e. voltage) is required to produce a current, as described by Ohm’s Law above. As per all electronic components, resistors dissipate energy as heat according to the equation:

### Resistors in Series

Resistors in series add:

*Resistors in series*

### Resistors in Parallel

Resistors in parallel add reciprocally:

*Resistors in parallel*