The electrical current flowing in an x-ray tube is measured in:

The electrical current flowing in an x-ray tube is measured in milliamperes. This unit is particularly relevant for x-ray machines because it represents the amount of electric charge flowing over a period of time in one thousandths of an ampere. In the context of x-ray production, the milliamperage setting directly affects the quantity of x-rays produced; it essentially controls the number of electrons that are generated and subsequently accelerate towards the anode to create x-rays.

In practical terms, an increase in milliamperes results in a higher exposure to the patient, as it increases the intensity of the x-ray beam. This precise measurement is crucial for ensuring that appropriate doses are delivered for diagnostic imaging without unnecessary exposure.

Understanding that while volts indicate the potential difference and watts measure power (which is a product of voltage and current), the specific current applied in x-ray tubes to manage the quantity of x-rays generated is expressed in milliamperes, making this answer the most accurate in this context.