What is abbreviated as 'A' in electrical measurements?

In electrical measurements, the abbreviation 'A' refers to Ampere, which is the standard unit of measurement for electric current in the International System of Units (SI). One Ampere is defined as the flow of one coulomb of charge per second. This measurement is fundamental to understanding how electric circuits work, as it quantifies the amount of electric charge that passes through a conductor over a specified period.

While the other options have their own scientific significance, they do not pertain to electrical measurements in the context of current. For instance, angle relates to geometric measurements, area pertains to the measurement of surfaces, and atom represents the basic unit of a chemical element. Therefore, Ampere is the only choice that accurately captures the essence of electrical measurements.