A piece of copper and another of germanium are cooled from room temperature to $77 \mathrm{~K}$, the…
A piece of copper and another of germanium are cooled from room temperature to $77 \mathrm{~K}$, the resistance of
each of them increases
each of them decreases
copper decreases and germanium increases
copper increases and germanium decreases
Solution
Copper is metallic conductor and germanium is semiconductor therefore as temperature decreases resistance of good conductor decreases while for semiconductor it increases.