🔍 Key Concepts

• Difference between external noise picked up by the antenna and internal noise created inside the receiver circuits • How receiver performance is quantified in terms of signal-to-noise ratio (SNR) at the input vs. at the output • Which receiver characteristic describes selectivity vs. which one describes internally generated noise

💭 Think About

• Ask yourself: Is this term describing noise coming from outside the receiver or noise produced by the receiver itself? • Consider how engineers compare a theoretically perfect receiver with a real receiver that adds some noise—what metric expresses that degradation? • Which of the options sounds like a measure (a number or ratio) rather than a descriptive ability like rejection or filtering?

✅ Before You Answer

• Identify which choices describe internal noise created by the receiver, not noise from the antenna or the environment • Separate functions like selectivity (rejecting nearby frequencies) from those that describe noise performance • Focus on which option could be expressed as a ratio or numerical figure comparing signal-to-noise at input vs. output