Why will current decrease when voltage increase in a transformer ? I 've just learnt it and I get confused. Assume there are 2 solenoids, the no. of turns of coils in the left sides one(with AC current) is less than that in right sides.By conservation of energy, V(left) x I(left) = V(right) x I(right). It is seemingly correct. Now, we consider only the right side one, assume V(left) x I(left) is constant. If the no. of coils of the right-side solenoid is doubled, the emf(voltage) induced will increase, as well as the current (I). However, the current will drop by conservation of energy. How can you explain why transformer current is inversely proportional to voltage ??? Would it have any difference if I replace the left-side solenoid with a rotating magnet? Thx ~ http://imageshack.us/photo/my-images/217/img20120725153619.jpg/ http://imageshack.us/photo/my-images/402/img20120725153931.jpg/ <-- will the current increased when i double the no. of turn of coils ?