If copper and silicon are cooled from 300 K to 60 K, then the specific resistance will:
1.  Decrease in copper but increase in silicon
2.  Increase in copper but decrease in silicon
3.  Increase in both
4.  Decrease in both

The specific resistance of a conductor increases with:

A \(6\)-volt battery is connected to the terminals of a three-metre-long wire of uniform thickness and resistance of \(100\) ohms. The difference of potential between two points on the wire separated by a distance of \(50\) cm will be:
1. \(3\) V
2. \(1\) V
3. \(1.5\) V
4. \(2\) V