# Tutorial: Circuit Basics¶

These notes are meant to accompany an in-class tutorial presentation, and may not necessarily stand alone. For reference, see also Basic Circuits.

## Electricity¶

• electrons, currents
• potentials, voltage
• metaphorical traps

## Schematics¶

• Notation, common symbols
• KCL
• KVL

(Images courtesy of wikimedia.)

## Digital Multimeters (DMM)¶

• purpose
• probe locations
• modes: voltage, resistance, current etc.
• later: the oscilloscope

## Resistance and Ohm’s Law¶

• visual guide
• Each resistor follows Ohm’s Law: $$V = i * R$$. This idea can be understood in several ways:
1. a voltage across a resistor will cause a current to flow through it: $$i = V / R$$
2. a current through a resistor will induce a voltage drop across it: $$V = i * R$$
3. the resistance is defined by the observed ratio of voltage drop to current flow: $$R = V / i$$.
• an empirical property
• an engineered property