2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/142979We study a model of random electric networks with Bernoulli resistances. In the case of the lattice Z^2, we show that the point-to-point effective resistance between 0 and a vertex v has a variance of order at most (log |v|)^(2/3) whereas its expected value is of order log |v|, when v goes to infinity. When the dimension of Z^d is different than 2, expectation and variance are of the same order. Similar results are obtained in the context of p-resistance. The proofs rely on a modified Poincare inequality due to Falik and Samorodnitsky.Final version, to appear in CMP (minor changes compared to version 3)ProbabilityMathematical PhysicsPrimary 60E15; secondary 31C20, 31A99, 31C45text