Final answer:
To measure the current in a circuit, an ammeter must be connected in series with the component or device in question. The series connection ensures a uniform current throughout the circuit branch for accurate measurement.
Step-by-step explanation:
To measure the current through a device or component, the ammeter must be placed in series with the device or component. A series connection is used because objects in series have the same current passing through them. This ensures that the ammeter will measure the total current flowing through the circuit branch. The ammeter should have a low resistance so as not to significantly affect the current it is designed to measure.
It is important to position the ammeter correctly in the circuit to obtain an accurate measurement. For example, if two resistors are connected in parallel to a battery, separate measurements with the ammeter in series with each resistor are required to determine the individual currents, while a single series connection would suffice if measuring the total current from the battery.