Which principle allows the calculation of the resultant electric field from multiple charges by summing the fields due to each charge individually?

Which principle allows the calculation of the resultant electric field from multiple charges by summing the fields due to each charge individually?

• A. Superposition principle
• B. Huygens principle
• C. Faraday's law
• D. Biot-Savart law

Answer: (A)

The principle at play is that electric fields add by superposition: the total field at any point is the vector sum of the fields produced by each charge. Because Coulomb’s law for each charge is linear and Maxwell’s equations in free space allow linear superposition, you can treat each charge’s field independently and then add them together to get the resultant field. In practice, you compute each individual field E_i at the point using E_i(r) = (1/4πε0) q_i (r − r_i)/|r − r_i|^3 and then sum: E_total = Σ E_i. The same idea holds for electric potential, where V_total is the sum of the potentials from each charge. Other concepts listed describe different phenomena: Huygens’ principle is about wavefront propagation, Faraday’s law concerns induction from changing magnetic flux, and the Biot–Savart law gives the magnetic field from currents. They don’t describe how static electric fields from multiple charges combine.

The principle at play is that electric fields add by superposition: the total field at any point is the vector sum of the fields produced by each charge. Because Coulomb’s law for each charge is linear and Maxwell’s equations in free space allow linear superposition, you can treat each charge’s field independently and then add them together to get the resultant field. In practice, you compute each individual field E_i at the point using E_i(r) = (1/4πε0) q_i (r − r_i)/|r − r_i|^3 and then sum: E_total = Σ E_i. The same idea holds for electric potential, where V_total is the sum of the potentials from each charge. Other concepts listed describe different phenomena: Huygens’ principle is about wavefront propagation, Faraday’s law concerns induction from changing magnetic flux, and the Biot–Savart law gives the magnetic field from currents. They don’t describe how static electric fields from multiple charges combine.