Two concentric circular loops lie in the same plane and share the same center

PHYSICS · Single correct · AP · Physics 2: Algebra-based · Magnetism and Electromagnetism · Magnetism and Electromagnetism

Problem

Two concentric circular loops lie in the same plane and share the same center. The inner loop has radius

3.0\,\text{cm}

and carries a current of

5.0\,\text{A}

that is counter-clockwise when viewed from above. The outer loop has radius

5.0\,\text{cm}

and carries a current of

3.0\,\text{A}

that is clockwise when viewed from above. Using

\mu_0 = 4\pi\times10^{-7}\,\text{T}\cdot\text{m/A}

, what are the magnitude and direction of the net magnetic field at the common center? (a)

2.1\times10^{-5}\,\text{T}

out of the page (b)

1.4\times10^{-4}\,\text{T}

into the page (c)

6.7\times10^{-5}\,\text{T}

out of the page (d)

1.0\times10^{-4}\,\text{T}

out of the page