Which of the following option is incorrect?

The correct answer is Option (1) → Alloys of metals usually have greater conductivity than that of their constituent metals.

The question asks for the statement that is wrong, so each option is judged as a statement.

Option (1) Alloys of metals usually have greater conductivity than that of their constituent metals — Incorrect statement. The irregular arrangement of atoms in an alloy scatters the electrons more, so alloys such as nichrome and manganin have a higher resistivity, that is a lower conductivity, than the metals they are made from.

Option (3) The resistivity of typical insulator is greater than that of metal by a factor of the order \( 10^{22} \) — Correct statement. Metals have \( \rho \approx 10^{-8}\) to \(10^{-6}\,\Omega\,\mathrm{m} \), and insulators such as glass and rubber have \( 10^{22} \) to \( 10^{24} \) times greater resistivity.

Option (4) The drift velocity will be changed when a steady current flows in a metallic conductor of non-uniform cross-section — Correct statement. The steady current \( I = neAv_d \) is the same at every cross-section, so \( v_d \) is larger where the area \( A \) is smaller.