Automotive Electronics Practice Test

Cycles per second are expressed in hertz, which is the unit of frequency defined as one cycle per second. The term "hertz" originated from the name of the German physicist Heinrich Hertz, who made significant contributions to the study of electromagnetic waves. In practical applications, hertz is commonly used to measure the frequency of electrical signals, sound waves, and other cyclic phenomena.

The other options refer to different concepts. The duty cycle represents the ratio of the time a signal is in an active state to the total time of the cycle, whereas pulse width refers to the duration of a pulse in a signal. Slope typically describes the rate of change of a signal but does not pertain to frequency. Understanding these definitions helps clarify why hertz is the appropriate term for measuring cycles per second.