Some important points to remember
- The resistance of a conductor does not change when the current through it is changed or the voltage across it is changed. When current is changed, the voltage across it is also changed so that the ratio V/I = R
- The value of resistance changes if the dimensions (length or area of cross section of the conductor) changes or the temperature changes.
- When the dimensions of a conductor is changed, the resistance changes, but the resistivity does not change.
- When temperature is changed, both resistivity as well as resistance changes.