Leslie

I'd have thought it would be safer to ask someone who is not a "sparky".

Les

legb4rsk

Here's a little tease to keep you thinking.

You have 3 light bulbs upstairs & 3 switches downstairs.
You can't see the light bulbs from where the switches are.
How do you determine which bulb is connected to which switch in one attempt?

Good luck & no prizes.

dpb

phone a friend ?

Ant

Ask the missis to shout down which goes off

legb4rsk

You're not allowed to use technical consultants.

Bubba po

If you mean by one attempt, that you have one chance to go and check which lights are on, then you do it this way:

Assuming all lights are off when you start, you turn the first two switches on, wait a few seconds then turn the second switch off again. Then you go upstairs to check. The light that is on is the switch that's still down, the light that is off but which is still warm is the other switch that you turned on, and the switch you didn't touch belongs to the bulb that is cold.

Lemon entry, my dear Watson.

legb4rsk

Another case solved ,Holmes.

sparkykev

Black to red
Red to black
Blue to pieces

Will

Swiss's house when he puts the kitchen lights on, from the outside


http://www.youtube.com/watch?v=Jnjj1G1lH8U