1. The problem statement, all variables and given/known data The figure shows a cross section across a diameter of a long cylindrical conductor of radius a = 2.92 cm carrying uniform current 151 A. What is the magnitude of the current's magnetic field at the center of the conductor? 2. Relevant equations Biot-Savart's Law 3. The attempt at a solution B for circular loop = ui/2r B = ui/2a B = 0.0032 T Which is the wrong answer, what happened?