- #1

CivilSigma

- 227

- 58

1. Homework Statement

1. Homework Statement

A wire has a current density of 6.67 × 10^6 A/m^2. If the cross-sectional area of the wire is 1.41 mm^2, what current does the wire carry?

With this current, how much time is required for 4.77 × 1020 electrons to pass any point on the wire?

## Homework Equations

Current = current density * area

Current = charge/time So, time = charge / current

## The Attempt at a Solution

For the first part I get: [tex]Current = 6.67\cdot10^6 A/m^2 * 1.41\cdot10^{-3} =9404.7A[/tex]

For the second part I get: [tex]time=\frac{4.77*10^{20} electrons \cdot 1.602\cdot10^{-19} C/electron}{9404.7A}=0.00813s[/tex]

And as I stated, I'm not getting the correct answer. As you can see my units all match up. Do you see a math error? Or have I misunderstood a concept.

Thank you,

-Sakon