A Circular Metal Loop of Radius 10 Cm and Three $I _ { 1 } = 20 \mathrm {~A}$

Multiple Choice

A circular metal loop of radius 10 cm and three long straight wires carry currents of $I _ { 1 } = 20 \mathrm {~A}$ $I _ { 2 } = 50 \mathrm {~A}$ $I _ { 3 } = 20 \mathrm {~A}$ and $I _ { 4 } = 40 \mathrm {~A}$ as shown in the figure. Each of the straight wires is 20 cm from the center of the loop. The axes are shown in the figure, with the +z-axis coming out of the paper. What is the y component of the resultant magnetic field at the center of the loop? (μ₀ = 4π × 10^-7 T ∙ m/A)

A) -54 μT
B) -60 μT
C) -50 μT
D) +60 μT
E) +50 μT