Two concentric spheres of radii R and r have similar charges with equal surface charge densities (σ). What is the electric potential at their common centre?
Options

Question

Two concentric spheres of radii R and r have similar charges with equal surface charge densities (σ). What is the electric potential at their common centre?

G1 Physics · Accepted Answer

Step 1: A uniformly charged spherical shell of radius a with surface density σ carries Q = 4πa²σ. Step 2: Potential everywhere inside that shell = kQ/a = σa/ε₀. Step 3: Sum contributions from radii R and r: V = σ(R + r)/ε₀.