why transformer don't work on DC supply?

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why transformer don't work on DC supply?
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Answer :

DC can not produce changing magnetic flux that's why.

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Answer :

A  DC  current  does  not  produce  a  changing  magnetic   field   which  is   capable  of  inducing   current   on   the   secondary    windings   of   a   transformer   through  mutual   induction   process.
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