Question
Question: Two charged particles are placed at a distance 1.0 cm apart. What is the minimum possible magnitude ...
Two charged particles are placed at a distance 1.0 cm apart. What is the minimum possible magnitude of the electric force acting on each charge?

2.3 × 10⁻²⁴ N
Solution
Given two charged particles separated by a distance r=1.0cm=0.01m, the electric force between them is given by Coulomb’s law:
F=kr2q1q2.
Assuming the charges are the smallest possible nonzero charges, we take them to be elementary charges: q1=q2=e=1.602×10−19C.
Substitute the values: F=(8.99×109)(0.01)2(1.602×10−19)2.
Calculate the numerator: (1.602×10−19)2≈2.566×10−38C2. (0.01)2=1.0×10−4m2.
Thus, F≈8.99×109×1.0×10−42.566×10−38=8.99×109×2.566×10−34.
Multiply the numbers: 8.99×2.566≈23.06, so, F≈23.06×10−25N≈2.3×10−24N.
Thus, the minimum possible magnitude of the electric force acting on each charge is approximately 2.3×10−24N.