Hi. I'm still confused about basic electricity. I have a USB power bank with two 1 A and one 2.1 A outputs. They all are specified with 5 V (all numbers from the manual, not measured myself). I just can't bring this into agreement with Ohm's law U=RI. Shouldn't the resistance R only depend on the load that is connected to the outputs? So how can both U and I be given beforehand? Or is one of them or both a maximum value?