JEE MAIN - Physics (2004 - No. 8)
A piece of copper and another of germanium are cooled from room temperature to $$77K,$$ the resistance of
copper increases and germanium decreases
each of them decreases
each of them increases
copper decreases and germanium increases
Selitys
Copper is a conductor, so its resistance decreases on decreasing temperature as thermal agitation decreases; whereas germanium is semiconductor therefore on decreasing temperature resistance increases.