Question

For a metallic wire, the ratio $\frac{V}{i}$ (where, V = applied potential difference and i = current flowing)

• A. is independent of temperature
• B. increases as the temperature rises
• C. decreases as the temperature rises
• D. increases or decreases as temperature rises depending upon the metal.

Answer 1

The correct option is B increases as the temperature rises

Metallic wires contain free electrons which help in conduction of electricity. As temperature increases, atoms start vibrating more vigourously, thereby increasing the number of collisions. These collisions hinder the movement of free electrons. Therefore, the resistance to movement of electrons is higher at higher temperatures. So, the ratio increases as temperature increases.