Question

As the temperature of a conductor increases, its resistivity and conductivity change. The ratio of resistivity to conductivity.

• A. increases
• B. decreases
• C. remains constant
• D. may increase or decrease depending on the actual temperature.

Answer 1

The correct option is A increases

Let $\rho$ be the resistivity and $\sigma$ be the conductivity of a conductor.

We know that, resistivity of a conductor is the reciprocal of the conductivity of a conductor.

$\therefore \rho \propto \frac{1}{\sigma }$

Therefore, Ratio of resistivity to conductivity = $\frac{\rho }{\sigma }$

Also, resisitivity of a conductor increases and conductivity of the conductor decreases with increase in temperature.

$\therefore \frac{\rho }{\sigma }=T^2$

Hence, the ratio of resisitivity to conductivity also increases with increase in temperature.