2.35 Center vs. corner of a square A square sheet has uniform surface charge density σ. Letting the electric potential φ be zero at infinite distance from the square. denote by φ) the potential at the center of the square and by the potential at a corner. Determine the ratio φ0/di·The answer can be found with very little calculation by combining a dimen- sional argument with superposition. (Think about the potential at the center of a square with the same charge density and with twice the edge length.)