I have read that in case of Van de graff generator $V=kQ/r$ where $r$ is radius of the sphere.
If that's the case, does the same voltage results in bigger charges in bigger radii?
[Physics] About voltage and charge of van de graff generator
chargeelectrostaticspotentialvoltage
Best Answer
If the charges (about some coulombs) numerically equalize or compensate (like doubling both the values simultaneously) the radius (in meters) of the sphere, then the potential indeed remains the same. $$V=\frac{kQ}r$$ The equation simply gives the relationship in $C/m$. Now, doubling the value of coulombs and meters would cancel each other out and so - you'd get the same value of potential...