Question

Superconducting cables conduct current with no resistance. Consequently, it is possible to pass huge currents through the cables, which, in turn, can produce very large forces. Two straight, parallel superconducting cables 4.5 mm apart (between centers) carry equal currents of 15000 A in opposite directions. Find the magnitude and direction of the force per unit length exerted by one conductor on the other. Should we be concerned about the mechanical strength of these wires?

What is the maximum current in the conductors if the force per unit length is not to exceed 8.6×10⁴ N/m ?

Express your answer to two significant figures and include appropriate units.

Answer 1

When two parallel current carrying conductors carry current in same direction attracts each other and

when two parallel current carrying conductors carry current in opposite direction repel each other and

so direction of force will be away from each other

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Force per unit length ,

where r is the distance between wires = 4.5 mm = 4.5*10^-3 m

= 4*10^-7 H/m ,I₁ = I₂ = 15000 A

ANSWER:

We should be concerned about mechanical strength of wires since the force is very large

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Maximum Force = 8.6*10⁴ N/m

Find Current