With increase in temperature, the thermal conductivity of steel

ANS:B - decreases

With an increase in temperature, the thermal conductivity of steel typically decreases. This phenomenon occurs because, at higher temperatures, the lattice vibrations within the steel lattice increase, which leads to greater scattering of electrons and phonons responsible for thermal conduction. As a result, the thermal conductivity of steel decreases as temperature rises. So, the correct answer is: "decreases"