# A piece of copper and another of silicon are cooled from room temperature to 75K. The resistance of

$\begin {array} {1 1} (A)\;Each \: of \: them \: increases & \quad (B)\;Each\: of\: them\: decreases \\ (C)\;Copper\: increases \: and\: silicon\: decreases & \quad (D)\;Copper\: decreases\: and\: silicon\: increases \end {array}$

Factual question. Copper is a metal whereas silicon is a semi-conductor.
Resistance of metals decrease with decreasing temperature
while that of semi-conductors increase.
Ans : (D)
edited Mar 14, 2014