Calculating the Thickness of a Doped Silicon Strip with Given Current and Width

[mrlucky0]

Homework Statement

A strip of doped silicon 270 µm wide contains 9.1E22 conduction electrons per cubic meter and an insignificant number of holes. When the strip carries a current of 110 µA, the drift speed of the electrons is 44 cm/s. What is the thickness of the strip?

Homework Equations

I=n*e*A*V

Where I is current, n is electrons per volume, A is cross sectional, v is drift velocity

The Attempt at a Solution

I've plugged into the equation above the variables given in the problem and solved for area. But how to find thickness, given the width? I think there's a missing link somewhere.

 

[aaroman]

Think about it: which area is that?

 

[mrlucky0]

It's the surface area of the strip. I've thought about it. I have the width and the surface area but I cannot solve for thickness.

 

[mgb_phys]

No it's the cross sectional area of the strip - does this help you find the thickness?

 

[mrlucky0]

Yes, just divide that by the width. Thanks!