Reverse Polarity: Difference between revisions
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* Thermal optics can also reverse polarity. Doing so switches between White Hot and Black Hot (Meaning that heat shows up as white or black, respectively.)
* In an MRI, the spinning dipoles slowly come out of sync with each other over time, which makes it difficult to observe them. The solution is to use a burst of radiation to reverse the polarity of the spin, which means that all the dipoles will sync up again after the same amount of time between the initial burst and the polarity reversal. This process can be repeated until other sources of error eventually overwhelm the signal.
* Permanent-magnet DC motors spin in the opposite direction when their power source is reversed. For 3-phase AC motors, this is achieved by swapping two of the phases.
* Electrolytic coating. If the given polarity makes a metal condense on the electrode, the reversed current will dissolve it back.
* Vascular plants get rid of air bubbles in the xylem by reversing the flow of water during the night.
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