The external magnetic field of induction B, in which a long perfectly conducting tube is located, is not completely shielded by the tube walls due to the fact that the mass of electrons is finite. The field partially penetrates the tube. The tube axis is directed along the magnetic field, and its radius r is much larger than the wall thickness h. The number of conduction electrons per unit volume of the tube material is n_e. Calculate the induction of the field penetrated into the tube in the case of B = 10 T, r = 1 mm, h = 0.1 mm, n_e = 10^20 cm^−3.