Should a Person Touch 200,000 Volts? A Van de Graaff generator experiment!

Jefferson Lab · 16.7M views · 2010 · 8:20

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Why Electrical Engineering Stack Exchange recommends it

Electronics Stack Exchange users link it as a concrete example when explaining that high voltage alone is not what harms you, and that current and available charge matter.

Recommended by 1 people across 1 different months, 2016 to 2020.

Why Physics Stack Exchange recommends it

Physics Stack Exchange askers cite it as the concrete example behind recurring questions about why very high voltage does not necessarily kill, usually before working through current, capacitance and body resistance.

Recommended by 1 people across 1 different months, 2020 to 2023.

What it is

A short live demonstration from Jefferson Lab in which a presenter touches a Van de Graaff generator charged to roughly 200,000 volts and explains why this does not seriously hurt them. It is one segment of a longer public science show on static electricity.

What people said

Recommends Siva Manasan · 2017-12 · Electrical Engineering Stack Exchange · on “How does electric current work?”

I am so confused about this ampere thing. Here are my questions. 1.A DC battery can deliver any amount of electric current we want(Before the battery burns out).For example, an led with 5 voltage and 1 amp rating can work in a battery of 9 v and a motor with the same voltage but higher ampere can also work in this battery.Right? 2.In the phone adapter(I am trying to charge my iPhone from a car igniter.), it is said to deliver 5v at 1A.Here why do they even mention the ampere if it is not needed and it all depends on the phone itself(I am thinking why can't the phone take ampere it needed like the led.I am not giving specific current to led.It is taking what is needed.) 3.Is it safe to measur

Recommends Fizzics · 2020-11 · Physics Stack Exchange · on “Why current drops when voltage increases?”

[this video] In the video above the man put a 200 thousands volt ball near a non-charged one and a very tiny current appear between them. But I think with high electric potential difference between them, the ions should be pushed with higher force since F=q.E and thus more charge particles moving through a region per time which means higher current. In reality there are many batteries that have the same voltage but different supply different currents. I know it has something to do with power but in my logic the battery is like a pump pushing electrons through conductor and it's voltage determines how much force it apply on the electrons to get them from cathode to anode which means with the same

Cites Rhezner · 2016-01 · Electrical Engineering Stack Exchange · on “Why can people touch high voltage?”

So I know that you need a certain current flowing through you to die, I've heard from some people "its the amps that kills you", and from others "Its the volts that drive the amps" and I realize that these are true according to ohms law v=ir or i=v/r. But I was watching this video: [this video] A guy touches a constant 200kv and i've seen a similar experiment in real life, assuming that his body has 100Kohm of resistance which is generous, thats 2 amps flowing through his body if you use ohms law, and realistically way more as there would be less resistance and it would decrease after it makes a circuit. How is this possible without him dying?

Cites Raghunandan Venkatesh · 2020-05 · Electrical Engineering Stack Exchange · on “I have a simple circuit with a relay with a SSR. I am getting leakage measured using a multimeter of ~4v. Is there a way to eliminate the leak?”

Firstly, Shock isn't due to voltage but due to current. check this [this video] Now coming to the circuit. From your explanation, I am sure if the multimeter is connected to the load terminal of SSR or the input terminal Assuming it's on the load terminal, even if the SSR is deactivated then the SSR load terminal will have some voltage at your terminal and you cannot judge an SSR using voltage. Typically, current flows when the voltage is zero across the SSR and this cannot be validated until there is a valid load for it Try to googling for Datasheet of the SSR you have. It will specify about the leakage current of the SSR. That should be your judging criteria

Cites Glowingbluejuicebox · 2021-11 · Physics Stack Exchange · on “What potential difference or current would kill a person?”

I was watching this [this video] YouTube lecture, and earlier in the vid he mentions 120 volts from a power outlet would kill you. So if human resistance is $300\ \Omega$ , $0.4 \rm A$ should be enough to do the job. Then he proceeds to touch a higher voltage of $200,\!000$ V and says its because the current flowing through him is low. Is it really? It should be around $700$ A. Which should have cooked this man inside out. There must be a mistake in my understanding, what was it?

Cites Gary Allen · 2022-06 · Physics Stack Exchange · on “Why is it safe to touch a Van de Graaff Generator?”

Let's say a typical (50cm radius) Van de Graaff generator (around 60pF capacitance) is charged to around 200kV (I am following the example seen in this video [this video] ). According to the formula for an RC circuit, and assuming the human body can be approximated by a resistance of about 1000 ohms (with wet hands and at such high voltages), a spike of maximum current I = V/R = 200 amps will occur at t=0 (formula for this on this page [LINK] ), however this will clearly not last long at all (until about 1 microsecond where the value is essentially zero after graphing the above equation). My first question is: are my calculations correct? Is there indeed an incredibly short but very high 200 amp

Cites donthababakka · 2023-04 · Physics Stack Exchange · on “Is $V=IR$ valid for a transformer when the input wattage is constant?”

Edit :- Sorry I didn't clarify before. My question is not duplicate. To be specific and understandable for all, please consider the voltage generator has a constant peak wattage, like a solar panel. I read this post [LINK] and this is not the answer I was looking for. So, this question is based on the fact that current in the primary side can't change with the changes to the secondary side because the wattage of the voltage generator is constant and the output voltage is also constant because the solar panel is working at its peak performance. With that consider following. I saw a video lesson on Youtube ( [this video] ) about a person touching 200000 V and still not get killed. The video told it