Which statement best describes the relationship between decibel sign and signal strength?

Which statement best describes the relationship between decibel sign and signal strength?

• A. Positive decibels indicate increasing signal strength; Negative decibels indicate decreasing signal strength
• B. Positive decibels indicate decreasing signal strength; Negative decibels indicate increasing signal strength
• C. Positive decibels indicate increasing signal strength; Negative decibels indicate decreasing signal strength
• D. They are unrelated to signal strength

Answer: (C)

Decibels express a ratio to a reference level, and the sign shows whether the signal is above or below that reference. A positive dB value means the signal is stronger than the reference (gain), while a negative dB value means it is weaker (loss). So positive decibels indicate increasing signal strength, and negative decibels indicate decreasing signal strength. This holds whether you’re measuring power or voltage (power uses 10 log, voltage uses 20 log), but in both cases the sign communicates direction of change.

Decibels express a ratio to a reference level, and the sign shows whether the signal is above or below that reference. A positive dB value means the signal is stronger than the reference (gain), while a negative dB value means it is weaker (loss). So positive decibels indicate increasing signal strength, and negative decibels indicate decreasing signal strength. This holds whether you’re measuring power or voltage (power uses 10 log, voltage uses 20 log), but in both cases the sign communicates direction of change.