Frequency is measured in:

## The Reasoning Frequency means **how many times something repeats in one second**. Think of a drum beat — if it beats 5 times per second, its frequency is 5 Hz (Hertz). The unit **Hertz (Hz)** is named after Heinrich Hertz and specifically measures "cycles per second" or "events per second." So 50 Hz = 50 repetitions every second. This applies to sound waves, electrical current (like our 50 Hz AC supply in Nigeria), light waves, or any repeating phenomenon. The formula connecting frequency (f) and period (T) is: **f = 1/T**, where T is measured in seconds. ## Why the Wrong Options Tempt You **Metres** measures distance/length — not how often something happens. **Seconds** measures *time itself* or the period (time for ONE cycle), not how many cycles happen. **Watts** measures power (energy per second) — completely different concept, though both use "per second." ## Quick Takeaway **Hertz counts repetitions per second** — whenever you see "how many times" or "cycles," think Hertz, not the time unit itself.