**Cycle of variation:** The process of changing the alternating electromotive force or current starting from zero to a maximum value, then decreasing to zero and then again increases in the reverse direction and reaches the maximum value and then starts decreasing and becomes zero is called a cycle of variation of the electromotive force current. In a word, it is the change in an alternating electrical sine wave from zero to a positive peak to zero to a negative peak and back to zero.

Example: 1- Cycle

One cycle, specified event, is measured 1 second in time which equals 1 Hz. As the CWNA mentioned, “alternating current is defined as a single change from up to down to up, or as a change from positive, to negative to positive”

** (5) Cycles **

Five cycles, specified events, measured 1 second in time which equals 5 Hz.

We are dealing with simple math – 1 and 5 cycles per second. Imagine for a moment 2,400,000,000 / 5,000,000,000 billion cycles in 1 second. High-frequency simple means there are more cycles per second.