Attenuation increases with longer path length and higher frequency.

Attenuation increases with longer path length and higher frequency.

• A. Increases with longer path length only
• B. Increases with longer path length and higher frequency
• C. Increases with higher frequency only
• D. Decreases with longer path length and higher frequency

Answer: (B)

Attenuation is the loss of signal strength as it travels through a medium. It grows with both how far the wave has to go and the frequency because energy is dissipated over distance and higher-frequency components tend to be absorbed or scattered more readily. In many media, the attenuation coefficient depends on frequency and increases as frequency rises. Mathematically, the amplitude after traveling a distance x is proportional to e^{-α(f) x}; as x increases, or as f increases (which raises α), the total attenuation becomes larger. So the statement that attenuation increases with longer path length and higher frequency is the best description. If it were only dependent on length, frequency wouldn’t matter; if it were only dependent on frequency, distance wouldn’t matter; and a decrease with distance or frequency is simply not consistent with how attenuation behaves in typical media.

Attenuation is the loss of signal strength as it travels through a medium. It grows with both how far the wave has to go and the frequency because energy is dissipated over distance and higher-frequency components tend to be absorbed or scattered more readily. In many media, the attenuation coefficient depends on frequency and increases as frequency rises. Mathematically, the amplitude after traveling a distance x is proportional to e^{-α(f) x}; as x increases, or as f increases (which raises α), the total attenuation becomes larger. So the statement that attenuation increases with longer path length and higher frequency is the best description. If it were only dependent on length, frequency wouldn’t matter; if it were only dependent on frequency, distance wouldn’t matter; and a decrease with distance or frequency is simply not consistent with how attenuation behaves in typical media.