Which of the following is true with regard to ammeters?

Ammeter function is predicated on the understanding of how they measure electrical current in a circuit. The correct answer emphasizes the necessity of observing proper polarity when connecting an ammeter in a DC circuit. This is essential because ammeters are designed to measure the flow of current, which has a specific direction in DC circuits. Incorrect polarity can lead to an inaccurate reading or potential damage to the ammeter itself.

In conductive pathways, current can only flow in one direction in a DC circuit, and ammeters need to be consistent with this directionality to record the proper value. This highlights the need for careful installation when integrating an ammeter in a circuit, reinforcing the importance of understanding electrical principles and the operation of measuring instruments.

The other choices reflect misunderstandings about ammeter operation or functionality. For instance, ammeters are not connected in parallel with a load; they should be connected in series to measure the total current flowing through the circuit correctly. Additionally, while shunts can be incorporated with ammeters to extend their range, the statement about shunts not being used is inaccurate. Lastly, ammeters are typically not capable of measuring extremely high resistances; that function is designated for ohmmeters, which focus on resistance measurements.