What does a megaamp measure?

A megaamp measures one million amperes. The prefix "mega" in the metric system denotes a factor of one million (10^6). Therefore, when discussing current in terms of megaamperes, it is important to understand that it refers to a very large electric current, much greater than typical household or industrial levels. This unit of measurement is often used in contexts where extremely high currents are involved, such as in large scale power systems, electrical grids, or scientific research involving high energy experiments. The other choices reflect much smaller units of current, which are not applicable when considering the definition of a megaamp.