As the temperature of iron is raised, what happens to the resistivity of the material?
Answer & explanation
Correct answer: option 2
ρ ∝ 1/t
t : relaxation time
As temperature rises, relaxation time decreases
Resistivity of most metals, including iron, increases as temperature rises. This is because vibrations of the atoms in the material disrupt the flow of electrons, making it harder for electricity to pass through.