Question

What are the sign and magnitude of a point charge that produces a potential of –2.00 V at a distance of 1.00 mm?

Final Answer

$-2.23\times 10^{-13}\textrm{ C}$

### Solution video

# OpenStax College Physics, Chapter 19, Problem 28 (Problems & Exercises)

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Video Transcript

This is College Physics Answers with Shaun Dychko. A charge creates a potential of negative 2.00 volts, 1.00 millimeter away and the question is, how much charge is there? So voltage from a point charge is Coulomb's constant times the charge divided by the distance from the charge and we can solve for

*q*by multiplying both sides by*r*over*k*. And so the charge then is the distance from the charge times the voltage divided by Coulomb's constant. So that's 1.00 millimeter written as 1.00 times 10 to the minus 3 meters times negative 2.00 volts divided by Coulomb's constant and that's negative 2.23 times 10 to the minus 13 coulombs of charge.