What is the back E.M.F in Transformer ?

What is the back E.M.F in Transformer ?
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Back emf in transformer is when apply voltage in primary side of transformer. This voltage produce flux according to Faraday law electro magnetic induction. This flux called mutual flux and this flux cut secondary coil and there produce another voltage and secondary voltage produce secondary flux and this secondary flux oppos the applied voltage according to lenz law. its called back emf of transformer
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