The voltmeter–ammeter method is probably the most basic means of measuring
resistance. It makes use of Ohm’s law and the assumption that the resistance is linear.
As shown in Figure 8.62, there are two basic configurations for this means of measurement:
the ammeter being before RX, which is in parallel with the voltmeter, and
the ammeter being in series with RX after the voltmeter. In the first case, the ammeter
measures the current in the voltmeter as well as RX; in the second case, the voltmeter