ARRL Technician Practice Exam

Which term describes the ability of a receiver to discriminate between multiple signals?

1. Selectivity

2. Stability

3. Distortion

4. Resolution

The correct answer is: Selectivity

The term that describes the ability of a receiver to discriminate between multiple signals is selectivity. Selectivity refers to a receiver's capability to isolate a specific signal of interest from other signals that may be present in the same frequency range. This characteristic is essential in communications systems, particularly in crowded radio environments where multiple transmitters may operate nearby on similar frequencies. A receiver with high selectivity can effectively filter out unwanted signals, allowing for clearer reception of the desired transmission. This minimizes interference and enhances the overall quality of communication, making selectivity a crucial aspect of receiver performance. Stability relates to the consistency of the receiver’s performance over time and under varying environmental conditions, while distortion refers to the alteration of the original signal as it is processed or transmitted, which does not specifically address the ability to distinguish between multiple signals. Resolution typically pertains to the ability to distinguish between closely spaced signals in terms of frequency or amplitude, which is more of a related but separate concept from the ability to select one signal from many.