Ever come across such argument or pondered such a question before ?
Perhaps, you may have come across a warning accompanying certain electrical gadgets/structure that reads "DANGER—HIGH VOLTAGE!". You don't see such dangers for current, in an old physics textbook of mine it was suggested that it's the current that's actually more dangerous. As a matter of fact, it's still believed today that it's the current that's more dangerous. Wait, what really is going on ?
Electricity despite being a fascinating phenomenon can also be mysterious. Arguments like this are often times raised when one gets in contact with an object supposedly carrying electricity and such person didn't get shocked when he/she is supposed to. Some time ago, a girl raised a question to some electrical engineering students of why she didn't get shocked after she licked honey from the port (the part that is normally connected to the phone to be charged) of a charger that was plugged to a live socket (it was carrying electricity). After she raised the question, everyone began to give their own explanation but eventually it led to an argument as to whether it was from the voltage or the current. I was there but didn't say anything, just paid attention to the conversations and arguments. The truth be told, her case required some in-depth analysis plus her question wasn't totally clear or that some key informations were missing. A lot of factors could have been at play, factors like
The kind of charger. Different chargers can have different output ratings depending on what it's intended to charge.
The kind of shock she meant. There's this kind of sensation we experience when we use our tongue to test for electricity from a power source (like batteries). Did she feel that but didn't consider that a shock ?
The size of the honey and how long (time) she did the licking.
The part of the port she licked.
Personally, i feel like it was most likely from the honey. The reason is because our tongue is by far a better conductor of electricity than our skin, the output ratings from the charger despite relatively low is enough for our tongue to detect, if she didn't detect it through that sensation we presented earlier, then the honey may have acted as an insulator or she licked a part of the port where there wasn't electricity.
So, how did trying to explain this phenomenon lead to voltage or current ?
Great question, some said it was probably due to low current while some others said it was probably due to low voltage, here i assume they neglected the conductivity of the honey and other factors i mentioned earlier. Low voltage or current could also be a factor but it's more complicated than you think.
Voltage and current are two different things but they both constitute what we call electricity, though there are others like resistance. Voltage is like the driving force, without it the electrons can't move. Current on the other hand is the number of electrons flowing per unit time - the higher the number of electrons, the greater the current at a fixed time. When we talk about the danger of electricity we talk about the harm it does to our body when we get exposed to it and it's mostly encountered when the electricity is high. However, electricity can be dangerous depending on a lot of factors not just on high voltage or current, as we shall now see
The Source
There are sources of electricity that produce both high voltage and at the same time high current, an example is the electricity from the power station - that we also find in our homes, and it is very dangerous.
There are sources of electricity that produce high voltage and very low current like the "Van de Graaff generator". The Van de Graaff generator was originally used as particle accelerators, if you are familiar with particle accelerators, you would know how very high the voltages are, especially when trying to accelerate particles to speed close to the speed of light. The funny thing is that if you get in contact with electricity from this generator it won't harm you and it's because the current is very little/almost nothing.
Then, there are sources that give low voltage and relatively high current - depending on time, an example is our phone battery or car battery. Electricity from these batteries on normal circumstances aren't dangerous but I have been shocked by a phone battery on few occasions but this is due to another factor which would be discussed later, the shock wasn't a dangerous one.
Here we can see that the source with both high voltage and current seems more dangerous at normal circumstances.
Type of electricity (AC or DC)
The electricity from the power station is AC (which reads Alternating current), it flows in both directions of the conductor. Conventionally, electricity first flows from positive to negative and then changes direction from negative to positive, it does this switching continuously leading to an oscillation. This is why you see things like 50/60 Hz (Hertz) in the ratings of some electrical gadgets, that is the frequency of oscillation.
Electricity from the output of your phone charger or battery (any battery) is DC (which reads direct current), it flows only in one direction which is conventionally from positive to negative, it doesn't switch or oscillate like AC electricity. AC electricity regardless of voltage/current are more dangerous than DC electricity and it's mainly because of frequency. In other words, both voltage and current are more dangerous if they are AC.
The part Of The Body
When our skin is dry, it's more of an insulator, it conducts electricity poorly and it protects our internal organs that are more sensitive to electricity. The reason why we feel the effect of high voltage and high current sources is because the high voltage first breaks down the insulating properties of our skin which then allows the current to go in and do the damages. In the case of a battery (which usually have current that can cause damage), the voltage is normally too low to break down the insulating properties of our dry skin, so the current won't be able to flow in to cause damage. In the case of the Van de Graaff generator there can be break down of the insulating properties of our skin but the current is too low to cause any damage. Our tongue (which happens to be an internal organ) is more of a conductor than our skin, regardless of the source we feel the effect through that sensation we discussed earlier.
In this case, the part of our body in contact with the electricity is a deciding factor.
State And Position of The Body
It is interesting to note that our skin can be in different states and these states can affect the resistance/conductance of our skin. A wet skin for example is a better conductor of electricity than a dry skin, i believe most of us are aware of this. Previously, i told us that i have been shocked by a phone battery on several occasions, did you know why ?
It's because i was sweating, sweat contains salt which makes it more conductive. Also, the sweat left traces of itself to the inside of my skin, what it means is that i had given the electricity the chance to enter the inside of my body (that is more sensitive to electricity) and that's why i felt the shock. It would have been more dangerous if the sweat left traces to my heart (the heart is known to be very very sensitive to electricity) or if the sweat happened to be a metallic conductor.
The way you position your body when you get in contact with electricity can also affect how it flows and how dangerous it can become regardless of voltage or current. For example, have you ever wondered why birds don't get electrocuted when they stay on a live wire (wire carrying electricity from the power station) ? - I guess we would discuss this in another article.
Duration (Time) of Exposure
The longer the exposure to electricity the higher the chances of danger. This is more evident when one gets in contact with high current and high voltage electricity, like the kind from the power station.
We can see now that the danger of electricity goes beyond high voltage or current. All the factors work together, just do the needful and stay safe.
It is here we conclude today's article, have a thoughtful day and till i come your way again next week.
For Further Reading
Thank you all once again for stopping by to read my jargons and also thank you @stemng, @lemouth and the @Steemstem team for your valuable supports.
Lastly, please don't forget to do the needful
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