## DHASHNI 3 years ago which is dangerous ac or dc ? explain

1. ajay_gautam

DC is more dangerous than AC Because in AC the current comes back to 0 then at maximum in negative phase. So there chances are left that person caught in AC will be saved

2. stormfire1

The question itself is silly. It's like asking what's more dangerous: being hit by a truck or by a bus. We can debate it all day but in the end both will ruin your day. AC is really no less dangerous than DC. Even though it's alternating it will still be quite impossible for you to let go if the muscles you need to use to do so are in the current path...the same goes for DC. The few milliseconds that AC crosses 0V is nowhere near enough to make a difference. It's also common knowledge that AC kills more people in industrialized countries than DC...but that's just because it's more prevalent at higher voltages. The bottom line is that it's the current (voltage / your body's resistance across the two points) that causes the tissue damage...whether it's AC or DC current is really inconsequential.

3. Ishaan94

I totally agree with stormfire.

4. ajay_gautam

Ok Stormfire, Tell me when I increase the frequency upto several KHz then why I didn't get shocked. even current flows from my bodies. For example as in Tesla Coil experiment we glows bulb in air even by keeping it in other hand it glows. where the shock goes. Would I've not been killed. Its my practical experience, and you the Voltage (potential difference) there was in KiloVolt. AC is less dangerous because it contain a term frequency, but DC doesn't

5. Ishaan94

You might have been wearing shoes. Next time, try it with 240V power line barefooted if you're so confident about AC.

6. stormfire1

In Tesla coils the output voltage and frequency is obviously very high. In order to understand why you don't feel a shock you need to know a little bit about how the nervous system works: For a nerve to "fire" as a result of an electric current, a significant number of neurotransmitters must cross the synaptic gap before the direction of current reverses causing them to move the other way. At frequencies above ~15-20 khz the nerves simply cannot react fast enough because the voltage (and current) is switching direction too fast. Even though you're not feeling a shock, tissue damage and death can still occur depending on the currents involved, their paths through your body and the length of the exposure. There are plenty of people out there that can attest to the fact that they felt muscle pain and tingling hours and even days after playing around with testla coils. And yes, tesla coils have killed people. There's a very good reason why you don't do these experiments barefoot and why there are so many safety warnings included with them.

7. ajay_gautam

I had tired it and you know I'm alive, I got a electric shock my whole left part of body was just sticked to ground for few seconds. And I know If it would DC, then I won't be alive today. I know how our nerves work you know, I can give shock at only 12V DC by some arrangement and the person will definetly die, but for AC there are quite possibility for saving. And If you have any doubt check your physics and see the EMF equation and wave form and just try to understand. and you know why I didn't get the shock while I was using tesla coil even barefooted, It was because the simple phenomena of AC that at high frequency current tries to travel nearer the outer body, so my nerve system in not affected at all. Check SKIN EFFECT and PROXIMITY EFFECT for more detail. And Definety the DC is more dangerous because it's inrespecitive with time but AC is respective....

8. Ishaan94

I see what you're trying to do here... "No man really becomes a fool until he stops asking questions. So never stop asking question, whether there is noone to answer them" -Copied from your Profile.

9. ajay_gautam

Human will die when the current will flow towards heart, if it doesn't flows towards heart then person will not die anyhow

10. ajay_gautam

thats another topic Ishaan talk about only this question I'll get back to you on that topic later

11. Ishaan94

Are you crazy, do you think AC current flows only on the outer boundry of a wire at high frequency?

12. ajay_gautam

yes, Ishaan, I know You'll not believe So first read skin effect.... then you'll know. and At even more high frequency current will flow through air

13. ajay_gautam

And this I don't think I know it. I have calculated it when calculating the inductance of long transmisison line

14. ajay_gautam

You know I am with electricity from 3 years because I'm an electrical engineer and I am observing every bit of its effect daily

15. ajay_gautam

Ishaan you have some doubt about this so I'm attaching a image in which read the underlined portion you'll come to know the truth. If you have still doubt then I can provide the mathematical proof of it

16. stormfire1

Ajay, you should read more on the skin effect: http://en.wikipedia.org/wiki/Tesla_coil (about half-way down) The text you posted was talking about the skin effect as it applies to conductors and you're trying to apply it to the human body. Yes, the human body conducts electricity but it has no where near the conductivity of a true conductor (copper, silver, etc). The fact is current still goes through your body...and not just on the outside...in Tesla coil experiments. At higher frequencies, it actually flows deeper into your tissues because that's where the least resistance is. Also, just because you've been shocked and did not die doesn't mean that it was because it was AC and not DC. It depends on a lot of factors which you are grossly oversimplifying here. I've been working with electricity for over 20 years and have been shocked on more than a few occasions (AC and DC...various voltages). Any one of those shocks could have killed me under the right conditions. I've learned over the years to ensure those conditions are never met. Anyway, I'm not going to argue this further since there is no point...your goal appears to be to defend your position rather than learn anything. Your 3 years of experience has you believing that you're an expert and that you can disregard any facts presented to you that you don't agree with.

17. ajay_gautam

ok stromfire, I'm wrong you're right.......Happy now