Consider the configuration of a system of four charges each of value +q. Find the work done by external agent in changing the configuration of the system from figure (i) to fig (ii).

Question

G1 Physics · Accepted Answer

Step 1: Write electrostatic energy U = Σ kqᵢqⱼ/rᵢⱼ, and use Wext = ΔU for a quasistatic rearrangement. For moving particles, conserve K + U. Step 2: Evaluate initial and final separations/potentials. Step 3: Solve the resulting energy equation for the requested distance, speed or work. Final: A: -(kq²/a)(3-√2).