🔍 Key Concepts

• Harmonics in AC (alternating current) and RF (radio frequency) systems • Relationship between a fundamental frequency and its higher-frequency components • Difference between frequency, impedance, power factor, and heating value

💭 Think About

• When you have a signal at some base (fundamental) frequency, what do engineers mean when they talk about its harmonics? • Which choice clearly talks about frequency itself, not about power, impedance, or heating? • In basic electrical theory, how are 2nd, 3rd, 4th ... harmonics typically described compared to the original signal?

✅ Before You Answer

• Identify which option directly refers to frequency rather than power or impedance-related ideas • Eliminate any choices that deal mainly with power factor or impedance, since those are separate concepts from harmonics • Confirm that the remaining choice correctly describes harmonics as being related to the fundamental (original) frequency in a simple integer way