Basic Qualification · B-005 Basic electronics and theory · B-005-007-002
What approximate range of frequencies can most humans hear?
- A 20 Hz to 30 000 Hz
- B 200 Hz to 200 000 Hz
- C 300 Hz to 3 000 Hz
- D 20 Hz to 20 000 Hz
Correct answer: D — 20 Hz to 20 000 Hz. From the official ISED question bank, verified word for word.
Why
Most humans can hear sounds vibrating between 20 cycles per second and 20 000 cycles per second, which covers the full range of speech, music, and everyday noises. The full explanation — and one for every question — is in Pro.
Practise this section
The theory: Ohm's law, power, series and parallel circuits, AC and DC, frequency and wavelength, decibels, and the metric prefixes the exam leans on.