Question

21. A peice of copper and germanium are cooled from room
temperature to 80 K. The resistance of:
(a) Each of them increases
(b) Each of tem decreases
A Copper increases and Germanium decreases
(d)Copper decreases and Germanium increases​

Answer 1

the theory related to this question is:-

a) conductivity of metallic conductor goes to up when temperature falling down.

b) conductivity of semiconductor goes to down when temperature falling down.

so, copper is metal and germanium is semiconductor