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jim hardy
Mar12-12, 12:40 PM
Sci Advisor
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An ideal transformer with open secondary would approximate an inifinite inductance
ie its primary would draw no magnetizing current.
and any load connected to the secondary could be represented as a load in parallel with primary .

A real transformer has imperfect core hence finite inductance so draws a small magnetizing current .

At any instant the energy stored in an inductor is [itex]LI^{2}/2[/itex]
and phyzguy's explanation above is 'spot on' .

Does that help?