As the temperature of a conductor increases, its resistivity and conductivity change. The ratio of resistivity to conductivity.
Formula used : Resistivity is given by
Where is the resistivity
σ is the conductivity
When temperature of a conductor is increases, its resistivity will increase and conductivity will decrease.
Ration of resistivity to conductivity is
Conclusion : When the temperature of conductor increases, the ratio of resistivity to conductivity will increase. Option A is correct.