I did an exercise today on my breadboard with an inductor that I made from a coil of 22 gauge stranded hookup wire wrapped in a helix coil around a 60d nail I found in my garage. The power source was a 9V battery. I took a measurement of just the battery fully open with my digital volt meter and found that I got a reading of .68A or 680 milliamps were being produced by the battery between its terminals in a circuit with little to no resistance (I hope my digital is not throwing me off here.) Upon connecting the 9V battery to my inductor I found that I was now measuring a fairly constant .04A or 40ma (from the same device so if my reading is off it will be proportionally so for all the readings). So I would have to say if I did the exercise correctly then my inductor is putting a serious load on the circuit. That leads me to my question which is if I know how much current and voltage is in a circuit before introducing the inductor into the circuit how am I to calculate how much current and voltage is being eaten by an inductor assuming that I am talking about a commercially bought inductor with defined specifications like for example a 100uh radial coil rated at 5A (this maybe to much inductor for a small 9V circuit maybe one smaller). How is the forward load found out if there is any change upon introducing a new inductor?