Question

The electron density in copper is 8.49 × 1028 electrons/m3. When a 1.00 A current is present in a copper wire with a 0.40 cm2 cross-section, the electron drift velocity, in m/s, with direction defined relative to the current density, is

Answer 1

Answer:

Drift velocity in m/s is $1.84 \times 10^{-8}\ m/s$.

Explanation:

Formula for Drift Velocity is:

$u = \dfrac{I}{nAq}$

Where I is the current

n is the number of electrons in 1 $m^3$ or the electron density

A is the area of cross section and

q is the charge of one electron.

We are given the following:

n = $8.49 \times 10^{28}\ electrons/m^3$

I = 1 A

A = 0.40 $cm^2$ = 40 $\times 10^{-4}$ $m^{2}$

We know that q = $1.6\times10^{-19} C$

Putting all the values to find drift velocity:

$u = \dfrac{1}{8.49 \times 10 ^{28} \times 40 \times 10^{-4}\times 1.6 \times 10^{-19}}\\u = \dfrac{1}{543.36 \times 10 ^{5} }\\u = 1.84 \times 10^{-8}\ m/s$

So, drift velocity in m/s is $1.84 \times 10^{-8}\ m/s$.