Current Electricity

The area of cross-section of a potentiometer wire is $6 \times 10^{-7} \mathrm{~m}^2$. The potential difference per unit length of the potentiometer wire when it is connected to a cell of negligible internal resistance and a resistor in series is $0.15 \mathrm{Vm}^{-1}$. If the current through potentiometer wire is 0.3 A , then the resistivity of the material of the potentiometer wire is