who is more dangerous 'AC' or 'DC' ?

Question

RELATED TO PHYSICS

Answer 1

More than 110 years ago, two men squared off in a technological battle that made Netscape vs. Microsoft look like a little league baseball game. In the late 1800’s, Thomas Edison and George Westinghouse were battling for control of the electric industry. Edison felt that direct current (DC) was the wave of the future. Westinghouse was convinced that alternating current (AC) was a safer and cheaper method of distributing electricity.

Edison had invested his resources in inferior DC power, and because of this, he saw safer and cheaper AC as a threat and did everything in his power to shut down Tesla and his business partner, George Westinghouse. The major advantage of AC had was the ability to step up the voltage and send it long distances over smaller wires and then step it back down for use by the customers. Try using a transformer with DC power and all you get is a big electromagnet.

To prevent Westinghouse and Tesla from capitalizing on the benefits of higher AC voltages, Thomas Edison launched an appalling campaign to discredit alternating current. The idea was to show that AC was too dangerous to use. His workers invited reporters to demonstrations where stray dogs and cats were placed on metal sheets and electrocuted with 330 volts AC. By using a hidden relay that interrupted the circuit, the animals merely yelped when up to 400 volts of DC was applied. The plan was to get AC circuits limited to no more than 300 volts. Keeping the voltage low would remove the major benefits of alternating current.

Next, Edison took out a commercial license to use AC. The world found out why after he'd made clandestine visits to Sing Sing prison. He'd created the electric chair. Now the American public would see what AC could do to a human being. Before the chair was first used on a fellow named William Kemmler, Edison's people started killing larger animals such as calves and horses in their AC demonstrations. "Is this what your wife should be cooking with?" they asked.

When poor Mr. Kemmler was taken to the chair to be -- as the Edison people put it -- "Westinghoused," the voltage was too low. A half-dead Kemmler had to be electrocuted a second time to finish him off. All this served Edison's purpose, of course. There was no need for Kemmler's passing to be a pleasant one. 8/6/1890

How many volts are used and for how long?
There has never been a standard protocol for this. Individual states and individual executioners have come up with their own practices. There are, however, certain limits. If the voltage is too low it takes too long, If it is too high or left on too long, the body is burned. The first execution used a voltage of about 1,700, although it was not officially recorded. The voltage has tended to increase over time and in the modern era the voltage is usually 2,000 to 2,200 volts at seven to twelve amps. Often the current is switched on and off several times, with the voltage often dropped between jolts. It usually is left on for less than a minute, although in many cases it is left on for as long as four or five minutes with repeated jolts if the prisoner does not die immediately.

2000 volts / 7 amps = 285 ohms.

Keep in mind that they shave the condemned person’s head and put wet sponges against the skin to make good, low-resistance connections. They don't want arcing to occur. An electric arc is a couple thousand degrees Fahrenheit.

"It's the volts that jolt but it's the amps that kill"

Answer 2

Sorry you are not correct there is no 1 second pause in between cycles, just fathom 50-60 hertz this is 50-60 polarity switchs a second with no pauses in between and even if there was, is there a single thing you can do 50 times in a second. The argument as to which is more dangerous has been in debate for more then a century. In the end AC wins out because AC requires a much higher voltage to arc a gap and therefore requires less effective insulation to be safe, this is not to say that AC can't be more dangerous then DC for some reasons. Because of the alternating polarity when electrocuted this becomes like being shocked many times extremely fast and this can easily cause fatal arythmia (heart attack) also because the polarity alternates it is much harder to force a short when being shocked by AC so the burns are slightly more severe in higher voltage ranges (such as used for sulpher lights or street lights). standing in a puddle and touching the terminals of a car battery would do nothing but get your feet wet by the way this is a common myth and when any books explain the dangers they are generally sited concern for the explosive hydrogen gas produced from the charging cycle and shorts because of the load potential. And I would not ever suggest touching a live wire from any part of your hand ever.

Answer 3

In spite of all the answers given to the contrary, AC is considered more dangerous because it has a higher peak voltage than the average and thus does damage when a DC delivering the same power would not. Further, AC does NOT "release you" after you touch the wire - it can put the heart into fibrilation at low currents and there a thousands of live victims who can testify that only someone knocking them clear or shutting off the power released them from the spasm that kept them on the wire. Of course, the hundreds and hundreds of dead people can not testify.
Most of us will never have experience with 100 volt or higher DC, so can not testify as to its effect.

Answer 4

Think of it this way, lightning is a direct current voltage. High tension transmission lines are alternating current. Either one will kill you because the voltage and current is too high.

Also, a car battery is only 12 volts DC, but is capable of producing 740 amps. An outlet in your house is typically 120 volts AC, but is usually limited to 15 amps through a circuit breaker or outlet. I've been shocked by a bad cord on a 120VAC outlet. It wasn't pleasant but did not kill me either. I do know that 12VDC with 740 amps has killed people and I have no plans on testing it.

In either case, the current is enough to kill you. Each person has a slightly different body chemistry and ability to conduct electricity. 30 milliamps or 0.030 amps is enough to stop your heart. It doesn't matter if it's 12,000 volts or 1.5 volts. It doesn't matter if it is AC or DC. Typically lethal currents are 100 to 200 milliamps. Also, 15 milliamps is typically the current needed to cause your muscles to contract resulting you being 'held' to the current.

The real problem is that the body is generally not a good conductor. It can dissipate a decent amount of current, providing you don't provide a good path. Grasping a wire in both hands provides a good path for current to pass through the heart. Touching it with one hand and passing through your foot, is not a good. Properly grounding yourself, you can actually contact thousand volt power lines. As a matter of fact, there are crews who work with live high-voltage AC power lines, but are required to provide grounding to avoid the shock. Electricity always follows the path of least resistance.

AC does alternate, but at 50 to 60 Hertz, its just not enough to allow the muscles to relax if sufficient current is applied. In instances where someone is 'thrown' off the power line, it is usually a circumstance where their initial position when them made contact allowed muscles to contract that forced them into a position that "pulled" them off.

Both AC and DC current could be applied to cause death. AC is used for power transmission because it can easily be transformed from higher to lower voltages or vice versa and is easily transmitted over long distances. DC current is used for batteries because it can be stored, while AC current for all intense purposes cannot be stored.

Also, most electrical devices transform AC currents to DC currents. That's how a radio that you plug into a wall can also use batteries. And yes, the DC current in the device can kill you, even if it only uses four "D" cell batteries.

Like someone else said, its the current that kills.

Answer 5

As we know in our houses we use AC line in our home for using elecitrical appliances. So, it is clear that DC is more dangerous than AC.
AC current has alternate follow of current and it throw away if anyone touch with it anyhow.
But Incase, of DC it stick to the victim and causes definetely for death if it contain high voltage.

Answer 6

Even thorgh AC has more voltage than DC, DC is more dangerous because,

u can easily escape from electric shock AC when it changes its cycle i.e. when it changes from +ve to -ve once it will become zero(0) volts. At that time u can withdraw ur hand.

In DC u will have constant voltage so u can't do so.

to feel shock minimum voltage is 30v

Answer 7

ac is the one with high voltage ranges above 220 V and DC usually deals with 3 -10 V

Answer 8

If DC was used at 240v in household appliances then somebody would die everyday. AC is very safe then DC at high voltages because it alters its charges. DC can be safely and easily stored in low voltage in batteries and that's why people have these wrong assumptions that DC is safe.

Answer 9

DC is dangerous than AC

Answer 10

it strictly depends on the voltage of d current. bt comparitively DC current is more dangerous as if a person touches a wire carrying DC current he/she gets stick 2 it. bt it doesnt happen wid AC. as AC current changes it direction after a time interval.