Light Switch
How can one know which light belongs to which light switch?

There are three light switches on the outside of a windowless room.
There are three light bulbs on the inside of this room.

If you are only allowed to flip the switches before you enter said room, how can you tell which switch is connected to which light bulb?

You are only allowed to enter the room once, and must know to which switch each bulb is connected to.

Switch on switch #1. Wait a minute, then switch it off again and switch on switch #2

Go into the room. The lamp which is lit is connected to switch #2.

Feel the other two bulbs. The one which is warm is connected to switch #1

The one which is cold must connect to switch #3

Light Switch Wiring

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