FCC Question Pool Review

Technician Class (Element 2) • 2022-2026

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Question T0B10

From subelement T0 - T0B

T0B10
Answer: C

Which of the following is true when installing grounding conductors used for lightning protection?

AUse only non-insulated wire
BWires must be carefully routed with precise right-angle bends
CSharp bends must be avoided
DCommon grounds must be avoided

Why is this correct?

Sharp bends create high impedance points that can cause lightning energy to arc or find alternative paths. Lightning follows the path of least resistance, so grounding conductors should have smooth, gradual bends to maintain low impedance. Right-angle bends (option B) are specifically wrong because they create impedance spikes. Insulated wire (option A) is acceptable, and common grounds (option D) are actually required for safety.

Memory tip

Look for the word 'sharp' as a red flag in lightning protection questions. Lightning behaves like high-frequency RF energy, seeking the smoothest electrical path. Any abrupt direction change creates impedance that lightning will try to bypass through your equipment instead.

Learn more

Lightning conductors work on the same principle as RF transmission lines—impedance matters. Sharp bends create reflection points where lightning energy can arc across the bend rather than following the conductor. This is why flat copper strap is preferred over round wire for RF bonding, and why professional lightning protection systems use gradual curves. The goal is creating the most electrically 'smooth' path to earth ground, minimizing any impedance discontinuities that could redirect dangerous energy.

Think about it

Why do you think lightning might 'jump' across a sharp bend in a grounding conductor rather than following the wire around the corner?