Physics, asked by Vaidyanathan, 1 year ago

When we touch switch with wet hands we get an electric shock but we know that human body is a good conductor of electricity then why don't we get shock when we touch the switch with dry hands????

Answers

Answered by vinay181
8
First, water alone does not conduct electricity! If you washed your hands in deionized water (water that has been essentially purified see: Distilled water) and then touched a switch, then you would not shocked even if you would under other conditions! The reason is that when salts dissolve in water, their ions dissociate, meaning you have + and - molecules ready to conduct charge. City and mineral water do not fall in this category so unless you were washing your hands in a lab with a RODI water tap, this is unlikely.You could be at the same potential as the wires in the switch. This is also unlikely, but if you are at the same electrical potential as another object, then you are very unlikely to get shocked. For example, take a look at this picture: 

The people repairing that live wire is not killed because they first touch the wire, equilibrating their potential, then begin work. This is the same reason that birds can sit on electrical wires (they enjoy the heat :). Note that in both cases there is no path to ground, ie. the charge can't 'pass through' the birds or the helicopter to the earth. This is important to note, because if there was a path to ground, this picture would be much more tragic. This also brings up an important distinction to make: electric charge doesn't hurt! Its the heat caused by the resistance in your body (if there is current flowing through your body) that causes the pain.
And as everyone already noted, the main reason you don't get shocked is likely because the switch casing is also insulating, meaning that electricity can't easily flow through the casing.

It is a myth that you get electrocuted when you touch a switch with wet hands, myth was originated from the experiences of people who do got electrocuted when they touched the doorbell switches when it was raining.

You do get electrocuted when the switches are wet (not the hands) . The reason for obvious is that when the circuit gets complete** between the conductors in the switch and your hands through the water.

When you touch the switch only with your hands wet, there are 99% chances that the water will not be enough to seep into the switch and get the circuit complete for you to be electrocuted. In this way your wet hand only touches the insulating plastic on the switch.

But when the switch is reasonably wet (due to rain or in the washrooms with the showers) then there is an 80% chance that the water is already touching the conductors within the plastic switch and is awaiting for you hand only to get you electrocuted.**

** definately you will haveto be barefooted on the ground to give the current an escapy way, otherwise it will still be an incomplete circuit and you wont get electrocuted. That is why it is recommended to whear rubber gloves and shoes /sandles while working with high voltages.

Hope this answers your question. But be on thesafer side, DO Not touch the switch with wet hands espesially if you are in Asia where there is 220V (designed to kill) .

if it help plz mark as brainliest............ .:)
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