I have been reading about the working of transformers at "no load" condition, that is when no load is connected to secondary side of the transformer. I don't understand why the transformer still draws a little current called "no load current." I read about it on different websites and in books and found that it is to set up magnetic flux in the system. Does drawing the current make the system stable or anything else, mustn't there be a requirement just like water has to go down a hill so that it can lower its potential energy?