Question Detail
Question
Find the magnitude of two equal charges if they repel each other with a force of 0.2N when placed 500mm apart in a vacuum (k = 9.0×10⁹).
Correct Answer
Option A is the correct answer.
Detailed Explanation
From F = kq²/r², q = √(Fr²/k) = √((0.2)(0.5)²/9×10⁹) ≈ 3.4×10⁻⁶C.
Hint
Rearrange Coulomb's law for two equal charges: q = √(Fr²/k).