Which statement correctly describes low frequency signals in this context?

• A. A low frequency signal provides better adherence to the conductor than a high frequency signal, but is more likely to be stopped by high resistance facilities such as joints.
• B. A low frequency signal provides worse adherence than a high frequency signal
• C. A low frequency signal cannot penetrate soil
• D. A low frequency signal is always preferred

Answer: (A)

The main idea here is how frequency affects how a signal travels along buried facilities. Low frequency signals couple more effectively to the metal conductor and tend to follow the line itself, so they stay on the conductor path better than high-frequency signals. At the same time, when the line encounters high-resistance discontinuities like joints, those points disrupt the signal more, making it easier for the low-frequency signal to be attenuated or stopped there. So the statement is correct because it captures both parts: better adherence to the conductor with low frequency, and greater chance of being hindered by high-resistance joints.

The other ideas aren’t accurate in this context: low-frequency signals do penetrate soil well, which contradicts the notion that they can’t penetrate; saying low frequency is worse at adhering contradicts the observed coupling behavior; and claiming low frequency is always preferred ignores practical trade-offs like resolution and noise, which depend on the situation.