Which mode impresses a signal directly onto the conductive material when hook-up is impractical?

• A. Inductive Mode
• B. Grounded Mode
• C. Reflective Mode
• D. Conductive Mode

Answer: (A)

Inductive mode is used when you can’t physically connect to the line because it couples the signal through a magnetic field rather than a direct electrical connection. A transmitter coil near the buried conductor creates a magnetic field that induces current in the line. The induced current carries the signal and can be picked up by the receiver without touching the conductor. This non-contact approach is exactly what’s needed when hook-up is impractical.

In contrast, other methods require direct access to the conductor (conductive mode) or rely on earth grounding or reflections, which isn’t suitable when you can’t hook up to the line.