# Calculate current with potentiometer

I've built a circuit on a breadboard using a 10K potentiometer, a 220 ohm resistor and a LED. They are connected in series. Using Ohm's law, you find that:

Total resistance $R = 10000 + 220 = 10220\Omega$

Battery: 9V.

$I = \frac{V}{R} = \frac{9}{10220} \approx 0.88mA$

Isn't that current too tiny for a LED? But even tough, it lights up at this resistance. Can anyone explain?

• The blue led in youtube.com/watch?v=yxoKb4d3gFA is powered at 0.3mA, 300 microamps. It's clearly visible in full daylight, when the white leds are on, and in the dark. I have other leds that are reasonably still on at 100 microamps and below. – Passerby Mar 25 '16 at 3:52
• I messed with an LED once that you could see glow by attaching one side to ground and holding the other side. Basically it was acting as a diode detector for all the line voltage noise that my body was picking up from the mains. – Daniel Mar 25 '16 at 3:54