`N = 300` turns  of thin wire are uniformly  wound on a permanent magnet shaped  as a cylinder
Channel: Doubtnut
Date: 2020-08-16

`N = 300` turns  of thin wire are uniformly  wound on a permanent magnet shaped  as a cylinder   whose  length  is equla to `l = 15 cm`. When  a current `I = 3.0 A` was passed  through the wring  the field outside  the magnet disappeared. Find the  coercive  force  `H_(e)` of the materail   from which  the magnet  was manufaucured.