Question

The voltage-current (v-i) graph of a metalic conductor at two different temperature t1and t2 is show below. at which temperature is the resistance higher

Answer 1

The mathematical expression for Ohm's law is:

                                   V=IR

Thus, graph between V versus I gives a straight line with slope R.

Since, slope at T2 is more than slope at T1. 

For metallic conductors, resistance is directly proportional to temperature. Thus, resistance is higher at T2