Final answer:
A multimeter set to the voltmeter function is the best tool for a starter circuit voltage drop test because it accurately measures the potential difference without significantly affecting the circuit's operation, and can also measure other electrical properties if needed.
Step-by-step explanation:
To perform a starter circuit voltage drop test, the most appropriate tool to use would be a multimeter set to the voltmeter function. A multimeter can measure voltage as well as other electrical quantities like current (with the ammeter function) and resistance (with the ohmmeter function), making it a versatile tool for various electrical measurements.
When measuring a voltage drop across a circuit, the multimeter should be connected in parallel with the component or segment of the circuit being tested. This allows the multimeter to measure the potential difference between two points without significantly affecting the circuit's operation. Specifically, for a voltage drop test, the multimeter will help in determining if there is excessive resistance in the circuit that could indicate a fault.
It is important to note that while an ohmmeter measures resistance directly and requires the component to be isolated from the circuit, a voltmeter does not and should never be placed in series with the component being tested, as it is designed to handle high resistance and measure potential difference in parallel.