Two thin, infinitely long, parallel wires are lying on the ground a distance d=3cm apart. They carry a current Io=200A going into the page. A third thin, infinitely long wire with mass per unit length λ=5g/m carries current I going out of the page. What is the value of the current I in amps in this third wire if it is levitated above the first two wires at height h=10cm above them and at a horizontal position midway between them?

3 answers

draw the forces, there's repulsion between the two equal wire against the third one

We have:
F = [uo.I1.I2/(2.pi.d)]*Ltotal

2*F*sin(a)= m*g = lamba*Ltotal*g

sin(a)=h/0.5d

Replace the values and you'll I.

By the way, have you done the one with the thick metal slab?
have you got the answer?
hai anonymous ,i stuck on dis question if u done for it plz help ???