A copper wire of length and cross-sectional area carries a current of

PHYSICS · Single correct · CBSE · Physics · Current Electricity · Current Electricity

Problem

A copper wire of length

2\,\text{m}

and cross-sectional area

1\,\text{mm}^2

carries a current of

3\,\text{A}

. The mobility of electrons in copper is

4.5\times10^{-3}\,\text{m}^2\,\text{V}^{-1}\,\text{s}^{-1}

and the free-electron concentration is

8.5\times10^{28}\,\text{m}^{-3}

. Find the magnitude of the electric field inside the wire. (a)

4.9\times10^{-3}\,\text{V m}^{-1}

(b)

9.8\times10^{-2}\,\text{V m}^{-1}

(c)

4.9\times10^{-2}\,\text{V m}^{-1}

(d)

4.9\times10^{-1}\,\text{V m}^{-1}