How Do You Calculate the Radius of a Wire Using Electrical Resistance Formulas?

[elenour]

Homework Statement

A wire of resistivity 3.14x10^-7 ohm m. and of length 200m. If this wire allows a flow of 2x10^19 electrons each second when its connected to a power supply of 64V, find the radius of the wire.

Relevant Equations

pi=3.14
e=1.6x10^-19 c

i really have tried all the formulas out there and can't seem to get a solid answer

 

[Gordianus]

Mr Ohm Is a good friend.

 

[vela]

Show us what you tried and tell us why you think it's wrong.

 

[elenour]

Show us what you tried and tell us why you think it's wrong.

I know the answers i get are wrong because its a multiple choice question and the answers are 10^-3 m, 10^-4 m or 10^-5 m and i haven't been getting close to any 10's.
I just want to know how to solve the problem

 

[haruspex]

I know the answers i get are wrong because its a multiple choice question and the answers are 10^-3 m, 10^-4 m or 10^-5 m and i haven't been getting close to any 10's.
I just want to know how to solve the problem

Per forum rules, you must post at least one of your attempts.

 

[David Abbot]

I think you are making some mistakes in the unit conversions, if we assume your approach to be correct.
1 electron contains 1.6*10^-19 C charge. So first multiply number of electron into charge, which gives us 3.2 A current. Use the formula V = IR, and calculate R. R comes out to be 20 ohms. Now calculate using the formula for resistance R= ρL/A, Find the area and then the radius of the wire according.