Two identical coaxial circular loops of radius R are separated by distance 2a and carry equal currents in opposite senses. What is the net magnetic field at the midpoint?
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Two identical coaxial circular loops of radius R are separated by distance 2a and carry equal currents in opposite senses. What is the net magnetic field at the midpoint?

G1 Physics · Accepted Answer

At the midpoint the two loops produce equal-magnitude axial fields. Opposite current senses make those fields opposite, so they cancel.