Question

How far from a 1.00 mu C point charge will the potential be 100 V? At what distance will it be 2.00 Times 10^2 V?

Answer 1

a)

$\fn_cm \large V=\frac{kQ}{r}$

$\fn_cm \large V=\frac{1}{4\pi\epsilon _0 }\times \frac{Q}{r}$

$\fn_cm \large 100V=9\times 10^9Nm^2C^{-2}\times \frac{1\times 10^{-6}C}{r}$

$\fn_cm \large r=90.0m$

b)

$\fn_cm \large V=\frac{1}{4\pi\epsilon _0 }\times \frac{Q}{r}$

$\fn_cm \large 200V=9\times 10^9Nm^2C^{-2}\times \frac{1\times 10^{-6}C}{r}$

$\fn_cm \large r=45.0m$