Question

 Calculate the electric potential and magnitude of electric field strength 0.378 m from a small sphere with 6.0E10 excess electrons.

Answer 1

$$V=k\frac{q}{r}=-9\cdot10^{9}\frac{(6\cdot10^{10})1.6\cdot10^{-19}}{0.378}=-230\ V$$

$$E=k\frac{q}{r^2}=-9\cdot10^{9}\frac{(6\cdot10^{10})1.6\cdot10^{-19}}{0.378^2}=-600\frac{V}{m}$$