alleryCommercial demagnetizers erase tools and hard disks using what kind of field?
AA steady field
BA growing field
CAn alternating field
DA gravity field
Answer & Solution
Correct answer: C. An alternating field
1. Demagnetizing needs the domains to be scrambled.
2. An alternating field is slowly reduced to zero.
3. A steady field would keep magnetizing instead.
_Source: Wikipedia, Magnet, Demagnetizing ferromagnets_
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