A galvanometer has a negligible resistance.
Many ammeters have several selectable shunts which provide their corresponding current meter ranges.
1000 A for full scale deflection, and in multiples of 10 between these extremes. Voltmeter A voltmeter, shown in Figure 2, is just a calibrated galvanometer with a series resistor so that the total resistance of the path is increased. The galvanometer range is calibrated for the current Ig passing through it. Ig Rg and Rg is the total resistance of the voltmeter. Meters are labeled to indicate the proper direction of current flow through them.