Answer to Question #320073 in Electricity and Magnetism for Ruby

Question

A point charge has a charge of 9.00 x 10^-11C. At what distance from the point charge is the electrical potential (a) 13.0 V? (b) 25.0 V?

Answer 1

We know that

Potential

$V=\frac{kq}{r}\\r=\frac{kq}{V}\\r=\frac{9\times10^9\times9\times10^{-11}}{13}=0.0623m$

Part (b)

$V=\frac{kq}{r}\\r=\frac{kq}{V}\\r=\frac{9\times10^9\times9\times10^{-11}}{25}=0.0324m$