Which term describes a circuit that suppresses the output of a radio receiver when the signal strength falls below a threshold?

• A. Squelch
• B. Spiral search pattern
• C. Sexual harassment
• D. Sentence fragment

Answer: (A)

The concept tested is how a squelch circuit works in a radio receiver. A squelch compares the incoming signal strength to a preset threshold and mutes the audio output whenever the signal is too weak. This prevents you from listening to hiss and noise during gaps between transmissions. When a usable signal above the threshold is present, the squelch opens and audio becomes audible again. This keeps listening comfortable and helps you recognize when an actual transmission is present. The other options don’t fit because they refer to completely different ideas: a spiral search pattern is a search-and-rescue technique, sexual harassment is unrelated, and a sentence fragment is a grammar issue.