Aclosely wound, circular coil with radius 2.30 cm has 740 turns. a. what must the current in the coil be if the magnetic field at the center of the coil is 0.0790 t ? express your answer to three significant figures and include the appropriate units. ii = 3.91 a submitprevious b. at what distance x from the center of the coil, on the axis of the coil, is the magnetic field half its value at the center? express your answer to three significant figures and include the appropriate units.