Final answer:
The warrant officer rank with a single 1/2 inch stripe with one break is the Warrant Officer 1 (WO1) in the U.S. military. It is the basic level of warrant officer and is denoted by a specific insignia worn on the uniform.
Step-by-step explanation:
The warrant officer rank identified by one 1/2 inch stripe with one break, centered on the outer face of the sleeve, is the Warrant Officer 1 (WO1) in the United States military. The insignia for a WO1 is a single black stripe that contains a break, and it is worn on both sleeves of the service dress uniform. The rank above WO1 is Chief Warrant Officer 2 (CW2), which is identified by a single stripe without a break.