mutual force interaction of two parallel conductors with current
1. Explain the mutual force interaction between two parallel current-carrying conductors.
Solution:
Two straight, parallel conductors through which electric currents flow exert magnetic forces on each other. If currents flow in the same direction, they attract; if they flow in opposite directions, they repel.
I1, I2 = electric currents, d = distance between conductors, l = active length of the conductor,
2.Two long, straight, parallel conductors in air separated by 1 m carry equal currents I1 = I2 = 1 A. Calculate the magnitude of the force that acts per unit length of each conductor.
Solution:
Given:
I1 = I2 = 1 A, l = 1 m, d = 1 m, k = 2.10-7 N·A-2
The required force is Fm = 2.10–7 N.
This example follows from the definition of the ampere—the base unit of electric current in SI.
The ampere is the constant current which, if maintained in two straight, parallel, infinitely long conductors of negligible cross-section, placed in vacuum and at a distance of 1 m from each other, would produce a force of 2.10–7 N per 1 m of length between these conductors.
3.Between two parallel conductors of a high-current line, separated by 20 cm, a force of 16 N acts on each meter of conductor length. Determine the magnitude of the electric current in the line.
Solution:
Given:
The line current is I1 = I2 = I = 4000 A.
4.At what distance must two parallel straight conductors be separated if each carries a current of 50 A and they exert a mutual force of 0.01 N per 1 m of length?
Solution:
Given:
I = 50 A, l = 1 m, F = 10-2 N, d = ?
The conductors must be separated by d = 5 cm.
5.An electric current flows through two straight, parallel conductors connected in series. By what factor must this current be increased so that, when the distance between the conductors is doubled, the magnitudes of the forces acting on the conductors remain unchanged?
Solution:
The current needs to be increased 21/2 time