why does this not light up

[stewieigp]

i plugged one side of a led to the ground hole in a wall socket and the other side to the positive (or neg) of a battery in it does not light up the LED.
can someone explain the physics of it. also if the unconnected side of the battery say the negative was connected to ground in florida, positive of battery connected to LED and the other leg of LED connected to earth in Ontario would that light up? What if the two places, ontario and florida were on different planets, completely disconnected?

needles to say that LED did light up when connect to the battery in both sides, so there was no error in the test. the socket is also grounded for sure.

[JoshMac]

Hi stewiejpg,

First of all, I cannot stress the importance of not playing around with mains unless you know what you are doing (this is not a dig at you, simply a safety statement).

Wall sockets dont really have a "ground" (if you are referring to negative), if you are referring to the earth pin, well thats kind of the same as putting that pin of the led into the dirt outside your house.

LED's are a DC device and the mains socket is AC.

LED's run at 2.2v, mains runs at either 110, 220 or 240v.

Any circuit, mains or dc (battery), needs to complete a circuit.

I sugguest picking up a getting started with DC electronics book (its where most people in here probably started), and staying away from mains.

Thanks,
Josh