# van de graaff

1. ### I Let current from a Van de Graff generator flow through you

Hi. I have two questions about the following video with a 200'000 V Van de Graaff generator: At 5:57 he touches ground, apparently feeling nothing. He explains this with a very low current and proceeds that the current from a 120 V outlet is high and might kill you. But with $I=U/R$ and...
2. ### High voltage in a small package (interplanetary civilization that communicates via particle beam)

<< Mentor Note -- thread moved to the Sci-Fi writing forum after starting in the technical forums >> Hey folks, I'm interested in the feasibility of providing high DC voltages (~kV) in a physically small and low mass package (~grams). The power source does not actually need to be very energy...
3. ### External-excitation Van de Graaff polarities

My question regards the polarities of the excitation supply and terminal in an external-excitation VDG. As you all probably know, external excitation VDGs use a voltage supply (usually 5,000-10,000V) to influence the charge on the lower pulley, instead of just relying on frictional contact to...
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### B Quick Question on Van de Graaff Particle Accelerators

Hi everyone. Just a small, quick question I have: Can negative ions be accelerated by a Van de Graaff particle accelerator? My initial reaction is no, because the terminal (the sphere with the charges allocated on the outside) is positive, which means negative ions would be attracted and not...
5. ### I Can a capacitor increase voltage beyond initial charge?

Question: If you charge a capacitor circuit and then separate the capacitor, does voltage increase beyond the initial source? It seams counter intuitive that if you plug a 9 Volt battery into two metal plates and pull the plates apart that you'll get massive voltage spikes, but that's what the...
6. ### I Leyden Jars increase spark length?

Good Evening/Morning/Afternoon Everyone, Question: Why is it that demonstrations of Van de Graff generators use Leyden Jars in series to get bigger sparks? If a spark gap's size determined by voltage, and Leyden jars are simply to be treated as capacitors which wouldn't increase voltage, why...
7. ### How to find the mass of a pith ball using electric forces?

1. Homework Statement A pith ball is charged by contact with a Van De Graaff machine, and is repelled away from the dome. It remains at its location. Using the chart given, what is the mass of the pith ball? Distance between centre of generator and pith ball...
8. ### B Why is current in Van De Graaff generator so low?

I know that current depends on the impedance and potential difference b/w two points so why does a van de graaff generator pose no serious shock hazard i.e. why the extremely low current between the generator and ground? As seen in this video demonstration the instructor safely touches the...
9. ### I How does this specific Van de Graaff generator work?

Hi. I have access to following Leybold Van de Graaff generator: The instructions and data sheet can be found here, but they don't give much insight. I have found different working principles of VdG generators. Some need the rising and falling sides of the belt to be closely together from top...
10. ### The force between charged and neutral object

1. Homework Statement I did a lab involving Van de Graaff generator. Basically, below the charged sphere, I put a neutral sphere on a scale and measure the difference in mass which then I can calculate the force acting on the neutral sphere. I repeated the experiment with different distance...
11. ### I Confused about electrostatic voltage and DC voltage

Hi everyone, I am a little confused conceptually about electrostatic voltage and DC voltage. I did my bachelors in biochemistry (where I’m working today), I’m learning/relearning physics as a hobby. I did well in high school physics and first year physics but I’m afraid I’ve forgotten most of...
12. ### Electrical DIY Van De Graaff Generator

Ok, so I'm building a Van De Graaff generator from parts i've been collecting for some time now. I have 2 hemispherical bowls that were supposed to line up perfectly to make the ball at the top. shipping has warped them just the slightest bit. I'm wondering if this will produce coronal leakage...