Final answer:
To safely measure a current that exceeds the rated capacity of an ammeter, you should either use a higher rated ammeter or employ a current transformer to step down the current to a measurable level.
Step-by-step explanation:
If the anticipated current to be measured in an ammeter exceeds the rating, the correct action to take would be to use a higher rated ammeter. This is because ammeters are designed to measure the flow of electric current and must be connected in series to the component whose current is being measured. They have very low resistance to ensure they do not significantly affect the current they are measuring. Using an ammeter with a current rating lower than what is expected in the circuit could lead to damage of the ammeter. Alternatively, if a higher rated ammeter is not available, another safe option is to use a current transformer, which can step down the current to a level that is within the ammeter's capacity without compromising safety or the accuracy of the measurement.