A very long wire carrying a current I = 5.0 A is bent into a semi-circle with a
ID: 2142128 • Letter: A
Question
A very long wire carrying a current I = 5.0 A is bent into a semi-circle with a diameter of 10 cm as shown in the figure. What is the magnitude of the magnetic field at the point P, halfway between the ends of the straight sections of wire and at the center of curvature of the semi-circle?
Explanation / Answer
For the magnetic field due to a wire:
B=(?_0 * I) / (2 * pi * r)
For the magnetic field due to the semi-circle:
B= (?_0 * I) / (4 * pi)
adding
(?_0 * I) / (2 * pi * r) + (?_0 * I) / (2 * pi * r) + (?_0 * I) / (4 * pi)