Which unit measures frequency in cycles per second?

• A. Hertz
• B. Hectoz
• C. Hz
• D. Hyper Hertz

Answer: (C)

Frequency is measured in cycles per second, which is defined by the unit Hertz. One cycle per second equals one Hertz, abbreviated Hz. Among the options, Hz is the standard symbol for this unit, so it precisely names the unit used to express cycles per second. The full name Hertz is correct too, but Hz is the conventional shorthand used in calculations and specifications. The other options aren’t standard terms for this unit—there isn’t a widely accepted unit called “Hectoz,” and “Hyper Hertz” isn’t used in frequency measurements.