Two insulated charged· conducting spheres of radii 20 cm and 15 cm, respectively, and having an equal charge of 10 C are connected by a copper wire and then they are separated. Then

After redistribution, charges on them will be different, but they will acquire common potential i.e.,kQ1r1=kQ2r2⇒Q1Q2=r1r2  As σ=Q4πr2⇒σ1σ2=Q1Q2×r22r12 ⇒σ1σ2=r2r1⇒σ∝1ri.e., surface charge density on smaller sphere will be more.