When 115 V is applied across a 9.66-m-long wire, the current density is . We have to calculate the conductivity of the wire material.

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We will assume that the electric field is uniform in the wire. As the potential difference across the ends of a wire of length 9.66 m is 115 V, the electric field in the wire will be

The current density,, and electric field,, are related as

where is the conductivity of the material. The current density in the wire is . Therefore, conductivity of its material will be