Correct Answer - Option 1 : Increase

**CONCEPT****:**

- The
**resistivities of metallic conductors **within a limited range of temperature are given by the following equation

\(⇒\rho _{T} = \rho _{0}[1+α (T-T_{0})]\)

Here, ρ_{T }= resistivity at a temperature T, ρ_{0} = resistivity at a reference temperature T_{0}, α = temperature coefficient of resistivity; the dimension of α is T^{-1}

- α is
**positive **for conductors and negative for semiconductors.
- According to the
**above equation**, a graph of ρT plotted against T would be a straight line i.e., **the resistivity of a metallic conductor increases with increasing temperature.**

**EXPLANATION:**

- As we discussed the
**conductor **has a **positive temperature coefficient,** so from the above equation, it can be easily said that **on increasing the temperature the resistivity of the conductor increases and vice versa is true**. Hence, the correct option is (1).