# Magnetic field from loop current

The above left diagram shows a circular current with radius $$2r$$ and current intensity $$I,$$ flowing in the direction of the arrows. The above right diagram shows two concentric circular currents with radii $$r$$ and $$2r,$$ respectively, and the same current intensity $$I,$$ flowing in the direction of their respective arrows. Points P and Q are the centers of their respective circular currents. If the magnetic field intensity at point P is $$B,$$ then what is the magnetic field intensity at point Q?

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