Question

The resistivity of metals is a constant quantity prove it

Answer 1

Answer:

Proofs are in the domain of mathematics and logic, not science. In science, we confirm or falsify theories. We use mathematics to derive expressions.

That said, the resistivity is not constant—not the resistivity of a metal nor the resistivity of anything else. To a first approximation, resistivity is a function of temperature for temperatures of the order of room temperature and above:

ρ=ρ0[1+α(T−T0)]

where α is the temperature coefficient of resistivity, T is the temperature, T0 is the reference temperature, and ρ0 is the temperature at the reference temperature. For most applications, the reference temperature is taken as 20 °C.