On increasing the temperature of a conductor, its resistance increases because

Step-by-step solution

The resistance of a conductor is given by the formula R = ml ne²A , where m is the mass of the electron, l is the length of the conductor, n is the number density of free electrons, e is the charge of the electron, A is the cross-sectional area, and is the relaxation time. When the temperature of a conductor increases, the thermal velocity of the free electrons increases. This leads to more frequent collisions between the electrons and the lattice ions. As a result of these more frequent collisions, the average tim