Magnetic force on a wire in a 100-wire bundle

[stryker123]

Homework Statement

A packed bundle of 100 long, straight, insulated wires forms a cylinder of radius R=.5cm

a. if each wire carries 2A, what are the magnitude and direction of the magnetic force per unit length acting on a wire located .2cm from the center of the bundle?

Homework Equations

B = μoI / 2(pi)r
?

The Attempt at a Solution

I found B to be .008T. but now I don't know what to do.

 

[stunner5000pt]

a packed bundle of wires that form a cylinder is a solenoid - thus you will ahve to find the magnetic field of a solenoid, and not that of a straight line ,as you have found

 

[Meir Achuz]

a packed bundle of wires that form a cylinder is a solenoid - thus you will ahve to find the magnetic field of a solenoid, and not that of a straight line ,as you have found

No. It is a straight wire.

 

[Meir Achuz]

Just use F/L=IXB.

 

[stunner5000pt]

No. It is a straight wire.

my mistake
i thought the wires curved to form a cylinder but instead we have a cylindrical bundle of parallel wires