Intro
The watt (W) is a convenience unit to describe the amount of work that current can do, as a factor of voltage and amperage, and is defined as:
Watts = Volts * Amps
Common Wattages
| Electrical Current | Voltage | Amperage | Wattage |
|---|---|---|---|
| Hair Dryer | 117V | 12A | 1,404W |
| 60 Watt Incandescent Light Bulb | 117V | ~0.5A | ~60W |
| iPad/Tablet Charger | 5V | ~2A | 10W |
| Netduino | 5V | 40mA | 0.2W |
Further Reading
For a much more in depth discussion regarding amps, see the wattage section in Part 2 of the Electronics Tutorial