13. A conductor has a surface charge density σ C/m2. The force per unit area on the surface is(A)0；(
問題詳情
13. A conductor has a surface charge density σ C/m2. The force per unit area on the surface is (A)0； (B) σ2/2εo N/m2； (C) σ2/εo N/m2； (D)2σ2/εo N/m2； (E) None.