A copper wire of length 2m and cross-sectional area 1mm2 carries a current of 3A. The mobility of electrons in copper is 4.5×10−3m2V−1s−1 and the free-electron concentration is 8.5×1028m−3. Find the magnitude of the electric field inside the wire.
a) 4.9×10−3V m−1
b) 9.8×10−2V m−1
c) 4.9×10−2V m−1
d) 4.9×10−1V m−1