Part A: Two long straight horizontal wires are suspended from the ceiling by ins
ID: 2092496 • Letter: P
Question
Part A:
Two long straight horizontal wires are suspended from the ceiling by insulated strings. The wires carry currents of the same magnitude I. The currents travel in opposite directions, so the wires repel each other and hang at equilibrium as shown.
The angle between the strings holding the wires is 15 degrees. Each of the four strings has a length of 1.2 m. What is the horizontal distance separating the two wires? Hint: Draw a diagram showing the wires in cross-section, so that the wires are perpendicular to the page.
Part B:
Refer to the previous problem. The mass per unit length m/L of each wire is .050 kg/m. What is the current in each wire? Hint: Refer to your diagram, and consider the balance of forces acting on one of the wires.
Explanation / Answer
A) d=2*1.2*tan(15/2)=0.316 m
b) (mg/L)Tan (7.5)=mu*I^2/2*pi*d
===>I=sqrt(2*pi*d*m*g*tan(7.5)/L*mu)=319.25 A