Which statement about the routing of cables to minimize interference is true?

• A. Keep data lines in close proximity to power lines.
• B. Route data lines behind metal walls with no separation.
• C. Avoid shielding unless required by regulation.
• D. Keep data lines separate from power lines and maintain adequate spacing.

Answer: (D)

Minimizing interference comes from keeping signal cables physically separate from power cables and ensuring there’s enough space between them. Data lines are susceptible to noise from power conductors and switching equipment, so parallel runs can introduce crosstalk and EMI that corrupt signals; separating them and maintaining adequate spacing reduces this coupling and preserves signal integrity. This is why the best choice states to keep data lines away from power lines and maintain proper distance. Shielding can help when EMI risk is present, but it’s not a substitute for good routing and separation, and it should be used appropriately with proper grounding. Routing data lines behind metal walls with no separation doesn’t guarantee protection and can still allow interference to creep in through openings or from nearby sources. Keeping data lines near power lines or avoiding shielding when not strictly required would both increase the chance of interference.