lets say you have a circuit consisting only of a resistor and battery. Is it absolutely necessary to connect an ammeter in series with the resistor to measure current through it, rather than in parallel? Current doesn't want to go through a resistor, so if you connect a much lower resistance (ammeter) parallel to the resistor, won't the current prefer to follow the path of least resistance? So you would still get a reading on the ammeter... What made me question this whole notion of always connecting ammeter in series is the fact that we did a lab in school and at first we accidentally connected the ammeter in parallel to a resistor and recorded that current. Then when we connected it in series, we got basically the same current reading for each of the three resistors we were measuring..