Final answer:
It is false that ammeters should be set to the lowest current scale before taking a measurement. Instead, they should start on the highest scale to prevent damage from excessive current and then possibly switch to a lower scale for accuracy.
Step-by-step explanation:
The statement that when measuring current in a circuit, the meter should always be set on the lowest current scale before performing the measurement is false. Instead, when connecting an ammeter to a circuit, you should start with the highest current scale to avoid damaging the meter if the current exceeds the meter's limits. Once you establish that the current is not too high for the meter, you can switch to a lower scale to get a more precise reading if necessary.
Ammeters are designed to have a very low resistance and are connected in series with the circuit to measure the full current flowing through it. They often contain a fuse to protect the meter from high currents that could damage it. Incorrectly connecting the ammeter could cause it to be in parallel, effectively lowering the circuit's resistance and allowing a higher current to pass through the ammeter, potentially damaging it.