- #1

- 17

- 0

*"If a Van de Graaff generator is charged to 50,000 volts, how much energy does it take to add an additional electron to the charge on the sphere?"*

(The charge of an electron is given as -1.6 x 10[itex]^{-19}[/itex]C)

My answer: (50,000 V)( -1.6 x 10[itex]^{-19}[/itex]C) = 8.0 x 10[itex]^{-15}[/itex] J

Er, I actually don't understand this at all, but if it's correct then meh.

Second question:

*"How would the voltage of the generator in Part (A) compare to the voltage of a larger Van de Graaff generator with the same amount of charge? To which generator could an electron be added with the least expenditure of energy?"*

According to my textbook,

So then by that reasoning, the larger generator should have more voltage for the same amount of charge. And by using the formula of volts x charge of an electron to find the energy needed to add an electron then it should take more energy to add to the bigger, higher voltage, generator.The voltage of a Van de Graaff generator can be increased by increasing the radius of the sphere or by placing the entire system in a container filled with high pressure gas.

BBUUUUUUUUTT... this is a bit contradictory to me because here https://www.physicsforums.com/showthread.php?t=229046 Doc Al has a different (opposite!) answer that makes sense but doesn't fit.

Can someone help me in clear English here? Thanks for any assistance!