# Questions about Van de Graaff generator

Only asking those questions because I can't afford to get a real generator.

1. If the voltage on the sphere was 50 kV, then I used a metal rod to discharge it and I connected a voltmeter to wire grounding the rod, will it read 50 kV?

2. Does the formula $V=kq/r$ apply for the generator? (According to some sites, it does.) If it does, which radius is meant? The hollow part radius? Will the thickness of the wall matter?