Which statement best captures the historical significance of Coulomb's experiments?

Which statement best captures the historical significance of Coulomb's experiments?

• A. They demonstrated the inverse-square nature of electrostatic forces
• B. They discovered electromagnetism
• C. They explained atomic orbitals
• D. They created the first voltmeter

Answer: (A)

The main idea here is that Coulomb’s experiments showed the force between electric charges obeys an inverse-square law: the force is proportional to 1 over the distance squared. In practical terms, if you double the separation between two charges, the force falls to one quarter; if you triple it, the force drops to one ninth. This is what Coulomb demonstrated with the torsion balance, translating tiny torques into measurable forces and revealing a precise mathematical relationship F ∝ 1/r^2. This was historically significant because it gave the first quantitative, universal law for an electrostatic force—Coulomb’s law. It not only described how charges interact but also provided a foundation for calculating the strength of forces at a distance, defining the constant of proportionality, and connecting electric phenomena with a clear mathematical form. The inverse-square nature also helped scientists recognize parallels with gravity, shaping later thinking about fields, potentials, and the way forces propagate in space. The other statements miss the mark because the experiments didn’t uncover electromagnetism as a whole, explain atomic orbitals, or result in the invention of the first voltmeter. Those developments came from different lines of work and more advanced concepts that built on but are distinct from this fundamental inverse-square relationship Coulomb established.

The main idea here is that Coulomb’s experiments showed the force between electric charges obeys an inverse-square law: the force is proportional to 1 over the distance squared. In practical terms, if you double the separation between two charges, the force falls to one quarter; if you triple it, the force drops to one ninth. This is what Coulomb demonstrated with the torsion balance, translating tiny torques into measurable forces and revealing a precise mathematical relationship F ∝ 1/r^2.

This was historically significant because it gave the first quantitative, universal law for an electrostatic force—Coulomb’s law. It not only described how charges interact but also provided a foundation for calculating the strength of forces at a distance, defining the constant of proportionality, and connecting electric phenomena with a clear mathematical form. The inverse-square nature also helped scientists recognize parallels with gravity, shaping later thinking about fields, potentials, and the way forces propagate in space.

The other statements miss the mark because the experiments didn’t uncover electromagnetism as a whole, explain atomic orbitals, or result in the invention of the first voltmeter. Those developments came from different lines of work and more advanced concepts that built on but are distinct from this fundamental inverse-square relationship Coulomb established.