The Basic lessons · Basic electronics and theory · B-005-007

Understanding Frequency, Wavelength, and Wave Basics

This lesson explains how alternating current cycles create frequency and wavelength, and why these concepts matter for radio. You will learn to identify audio ranges, harmonics, and the relationship between speed and distance in a signal.

This lesson is part of SignalPrep Pro. The subsection's 11 exam questions are free to practise: practise B-005-007.

What this subsection asks

• What is the term for the number of times per second an alternating current completes a positive to negative cycle?
• What approximate range of frequencies can most humans hear?
• Why is the range of frequencies from 20 Hz to 20 kHz termed audio frequencies?
• Electrical energy at a frequency of 7125 kHz is in what frequency range?
• What is the name for the distance an AC signal travels during one complete cycle?
• What happens to a signal's wavelength as its frequency increases?
• What happens to a signal's frequency as its wavelength gets shorter?
• What does 60 hertz (Hz) mean?
• Two AC waveforms have the same frequency, but their cycles do not begin at the same instant. What term describes that timing difference?
• What is the shape of the waveform of the electricity supplied from a household receptacle?
• A signal is composed of a fundamental frequency of 2 kHz and another of 4 kHz. What name is given to the 4 kHz signal?