which switch corresponds to which light bulb?

+1 vote
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There are three switches downstairs. Each corresponds to one of the three light bulbs in the attic. You can turn the switches on and off and leave them in any position.
How would you identify which switch corresponds to which light bulb, if you are only allowed one trip upstairs?

posted Sep 2, 2014

First we have to turn ON first switch and have to wait for 5 minutes, then we have to turn OFF it and turn ON the second switch and we have to check by going upstairs, the bulb which turned ON will corresponds to the second switch and we have to touch the remaining 2 bulbs, the one which is hot will corresponds to the first switch, the one which is neither hot nor ON will corresponds to the third switch.

answer Sep 2, 2014 by anonymous
+1 vote

Turn ON first switch and then wait for some moments.And Switch Off it, Then Switch On Second One.Go Up Stairs. Check the bulb which is glowing , that is Second Switch Control. Then Test remaining two with hand, Which feels your hand heat , that one is first switch control.

answer Sep 4, 2014

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