The Potential Difference Between Two Ends of a 45-Cm Length $\times$

Multiple Choice

The potential difference between two ends of a 45-cm length of copper wire (1.7 $\times$
10^-8 $\Omega$ ·m) is 1.5 V. The magnitude of the current density in the wire is

A) 1.0 $\times$
10⁸ A/m².
B) 1.5 $\times$
10⁸ A/m².
C) 2.0 $\times$
10⁸ A/m².
D) 2.5 $\times$
10⁸ A/m².