Question

A source charge of 3 µC generates an electric field of 2.86 × 105 N/C at the location of a test charge.

What is the distance, to the nearest hundredth, of the test charge from the source charge?

k equals 8.99 times 10 Superscript 9 baseline N times Startfraction meters squared over Coulombs squared.





m

Answer 1

Use E = kQ / r^2 so r = sqrt(kQ / E).

r = sqrt( (8.99×10^9 N·m^2/C^2)(3.0×10^-6 C) / (2.86×10^5 N/C) )
= sqrt(0.094336 m^2)
= 0.307 m ≈ 0.31 m.

Answer: 0.31 m.