MRI machines work on the principle that hydrogen atoms can behave like little magnets. When the magnet is aligned with an external magnet, it has zero energy. When the magnet points the opposite way, it has some energy Eo. If I have two hydrogen atoms, what fraction of the time will I observe the highest entropy state: one atom pointing with the field and one atom pointing against it? UMassAmherst Energy = 0 H Energy = 0 H S S External Magnet Physics EXAM QUESTION H Energy E H Energy = Eo IN a. 50% of the time. Ob. 75% of the time. OC 25% of the time. Od. Since this is the highest entropy state, you will observe this configuration 100% of the time. e. You will never observe this state.

MRI machines work on the principle that hydrogen atoms can behave like little magnets. When the magnet is aligned with an external magnet, it has zero energy. When the magnet points the opposite way, it has some energy Eo. If I have two hydrogen atoms, what fraction of the time will I observe the highest entropy state: one atom pointing with the field and one atom pointing against it? UMassAmherst Energy = 0 H Energy = 0 H S S External Magnet Physics EXAM QUESTION H Energy E H Energy = Eo IN a. 50% of the time. Ob. 75% of the time. OC 25% of the time. Od. Since this is the highest entropy state, you will observe this configuration 100% of the time. e. You will never observe this state.