Magnetic forces between parallel wires

[aliaze1]

Homework Statement

What is the force magnitude on the first, second, and third wires in the figure?

Homework Equations

(μ₀L I₁ I₂)/(2πd)

μ₀ = 1.2566*10^-6

The Attempt at a Solution

Substituting 0.5 as L, 0.02 as d and 10 as I₁ and I₂ I get 5*10^-4,
which comes up as incorrect...what am I doing wrong?

thanks!

 

[rock.freak667]

well if you did some more about current carrying conductors.
you may come across the formula

$$F=\frac{\mu I_1 I_2 l}{2 \pi d}$$

but are you sure you converted cm to m?

 

[aliaze1]

yea that us the formula i used...and i converted everything...the numbers i put in post 1 are the numbers i used for d and L respectivly

 

[rock.freak667]

What is the correct answer? well...you would have to find the resultant force on wires 1 and 3...

 

[aliaze1]

idk the correct answer...

and since the wires are the same, wouldn't some cancel each other out? (due to the direction of the current)

 

[aliaze1]

well the force in the second wire zero

 

[rock.freak667]

yes the force in the 2nd wire is zero, so you should have to only find the force of attraction of wires 1 and 3...

EDIT: thing to remember...like currents attract, opposite repel

 

[doc.madani]

So the just say that the first wire was going in the opposite direction to the other 2 wires... How would u calculate the force acting on wire 1 due to wire 2 (and wire 2 was going the opposite direction) and 3 ?

1<---
2 --->
3 --->