find the correct switch.....

[psuresh1982]

In a building ground floor a set of three light switches are located. One of switch turns on the second floor light. Other two switches do nothing. you allowing to go second floor for only one time and you can't see second floor light from ground floor. How can you find which switch get the control?
[ You didn't have any materials related to checking the power ]

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suresh

[kalayama]

I can answer this question assuming that the light is a "Bulb". The point here is bulbs get heated up.

Keep any switch on for around 10 mins. Switch it off and switch on any of the remaining two switches. Go to second floor, check if the light is blowing, if yes, then the switch that is ON is the switch. If the light is not glowing, touch it. If it is hot , then the first switch is the switch otherwise the remaining switch(That was never turned on) is the switch for the light.

Cheers!
Kalayama

[Manojks]

I think the same question is posted previously...
Link http://www.geekinterview.com/talk/19...-solve-it.html

Thanks
Manoj

[psuresh1982]

sorry manoj....i didn't notice that one...satisfy this mistake i post a new one here....

New Puzzle.....

In a building ground floor a set of four light switches are located. One of switch turns on the second floor light. Other three switches do nothing. You may flip the switches as often and as many times as you like, but you allowing to go second floor for only one time and you can't see second floor light from ground floor. How can you find which switch controls the light?

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suresh

[Manojks]

Hey Suresh,

Step 1. Dont ON the first switch
Step 2. Switch on the second switch
Step 3. Switch on the third switch and keep for 2 minutes and switch OFF
Step 4. Switch on the fourth switch and keep for 4 minutes and switch OFF

Go to the 2nd floor....
If u find the bulb glowing the the switch is 2nd switch
If u find the bulb get less heaten then 3rd switch
If u find the bulb get more heaten then 4th switch
If u find the bulb neither glowing nor heated up then 1st switch

The Steps to be followed in the way i have written sequently...

Thanks
Manoj

[kalayama]

How exactly do you identify if the bulb is "more" heated or "Less"? What is the refference point? I don't think you can identify the difference between 2 mins of heating and 4 minutes of heating....

Just wondering...

-kalayama

[Manojks]

Kalayama thats y i put 2 minutes in the third step... I want the bulb to cool down for 4 minutes... I think we can clearly identify the bulb if its heated up for 4 minutes or its heated up for 2 minutes and cooled down for 4 minutes... I'm sure even if the glass part get cooled down completely still the metal part of the bulb will be hot... In that way u can identify...

Thanks
Manoj

[kalayama]

Hmmm...
Makes sense. But I was just wondering if there was any other possible solution.
Yes. your arguments look corrent.

Thanks.

Cheers!
Kalayama