🔍 Key Concepts

• Frequency modulation (FM) basics: carrier frequency, modulating (audio) frequency, and frequency deviation • Meaning of frequency deviation in FM (how far the carrier moves from its center frequency) • How a ratio can describe how "strongly" the carrier is being modulated in FM

💭 Think About

• Which options clearly describe a ratio involving frequency deviation and modulating frequency rather than unrelated ideas like processor settings or signal-to-noise? • Look closely at the wording: does modulation index use average values, instantaneous values, or maximum/"peak" values? • Is modulation index tied to audio frequency content (modulating frequency) or to receiver performance measures like SNR?

✅ Before You Answer

• Verify that the correct definition involves a ratio of frequency deviation to modulating frequency. • Check whether the index is defined using maximum deviation and the highest modulating (audio) frequency present. • Eliminate any choices that mention things not part of the core FM definition, such as generic processor terms or performance metrics like SNR.