2
$\begingroup$

When I magnetize water by circular magnets of strength 0.8 T, how long will the magnetism be present in the water? I mean, how many days will it be in the water?

$\endgroup$

closed as off-topic by Aaron Stevens, user191954, JMac, John Rennie, GiorgioP Feb 28 at 21:04

This question appears to be off-topic. The users who voted to close gave this specific reason:

  • "Homework-like questions should ask about a specific physics concept and show some effort to work through the problem. We want our questions to be useful to the broader community, and to future users. See our meta site for more guidance on how to edit your question to make it better" – Aaron Stevens, Community, JMac
If this question can be reworded to fit the rules in the help center, please edit the question.

  • $\begingroup$ Hi venkatesh, welcome to Physics SE. Please note that you have to show your own effort in answering your question, and point out to us, where your actual problem is. $\endgroup$ – flaudemus Feb 28 at 18:40
3
$\begingroup$

The quantity you're asking for is called the "relaxation time" and is useful when performing NMR. There are many tables for this sort of thing, but just going off of Wikipedia, the atomic nuclei for water should lose their magnetization in about 1 second. The electrons, which are much more exposed, lose their magnetization even faster than that.

$\endgroup$
  • $\begingroup$ The medical literature on MRI has loads of data on T1 relaxation times in various tissues and tumors. $\endgroup$ – Bert Barrois Feb 28 at 14:14

Not the answer you're looking for? Browse other questions tagged or ask your own question.