Here is the solution to the Three Bulbs Three Switches Puzzle
Let's name the three switches as S1,S2,S3.
If we had only two switches and two bulbs, we could have just turned one switch "on" and the other "off" and we can identify the two. However, to our disadvantage, we have three switches and that is what makes this puzzle interesting. To find the answer to this puzzle, we should think outside the box.
We will switch "on" S1 and S2 and keep S3 turned "off". Don't go to the other room yet because we can't identify S1 and S2 because both bulbs B1 and B2 will be glowing. Wait for some time and turn S2 "off".
Now, after going to the next room, we know 1 bulb is glowing. The switch of that bulb is S1. We have two bulbs which are not glowing. Here is the twist !!
Touch the two bulbs and see which one is more hotter. The switch of the hotter one will be S2 because it was switched "on" for some time and at that time, electricity was passing through the bulb and this electricity inturn caused heating effect.
Heating effect of Electric Current is the concept that we are dealing with here.
If you know about current I and potential difference V, then heat produced can be calculated according to equation
H = VIt (t - time)
Let's name the three switches as S1,S2,S3.
If we had only two switches and two bulbs, we could have just turned one switch "on" and the other "off" and we can identify the two. However, to our disadvantage, we have three switches and that is what makes this puzzle interesting. To find the answer to this puzzle, we should think outside the box.
We will switch "on" S1 and S2 and keep S3 turned "off". Don't go to the other room yet because we can't identify S1 and S2 because both bulbs B1 and B2 will be glowing. Wait for some time and turn S2 "off".
Now, after going to the next room, we know 1 bulb is glowing. The switch of that bulb is S1. We have two bulbs which are not glowing. Here is the twist !!
Touch the two bulbs and see which one is more hotter. The switch of the hotter one will be S2 because it was switched "on" for some time and at that time, electricity was passing through the bulb and this electricity inturn caused heating effect.
Heating effect of Electric Current is the concept that we are dealing with here.
If you know about current I and potential difference V, then heat produced can be calculated according to equation
H = VIt (t - time)
