In Coulomb's law, what does the symbol k represent?

In Coulomb's law, what does the symbol k represent?

• A. The gravitational constant
• B. Boltzmann's constant
• C. Coulomb's constant
• D. Planck's constant

Answer: (C)

The symbol in Coulomb’s law is Coulomb’s constant, a proportionality factor that fixes the strength of the electrostatic interaction between two point charges. It appears in the equation F = k q1 q2 / r^2 and ensures the units and numerical values line up with experimental measurements. In vacuum, this constant equals 1/(4π ε0), where ε0 is the permittivity of free space, so k ≈ 8.99 × 10^9 N·m^2/C^2. The other constants—G for gravity, k_B for thermodynamics, and h for quantum relations—are different physical constants and do not belong in Coulomb’s law.

The symbol in Coulomb’s law is Coulomb’s constant, a proportionality factor that fixes the strength of the electrostatic interaction between two point charges. It appears in the equation F = k q1 q2 / r^2 and ensures the units and numerical values line up with experimental measurements. In vacuum, this constant equals 1/(4π ε0), where ε0 is the permittivity of free space, so k ≈ 8.99 × 10^9 N·m^2/C^2. The other constants—G for gravity, k_B for thermodynamics, and h for quantum relations—are different physical constants and do not belong in Coulomb’s law.