Magnetic Shielding If all protons absorbed the same amount of energy in a given magnetic field,not much information could be obtained. But protons are surrounded by electrons that shield them from the external field. 。 Circulating electrons create an induced magnetic field that opposes the external magnetic field. Chapter 13 9 Chapter 13 9 Magnetic Shielding • If all protons absorbed the same amount of energy in a given magnetic field, not much information could be obtained. • But protons are surrounded by electrons that shield them from the external field. • Circulating electrons create an induced magnetic field that opposes the external magnetic field