Correct AnswerB. Lightning rod (air terminal)
Quick Explanation
The cone-of-protection method estimates the zone shielded by a lightning air terminal/lightning rod. A geometric protective zone is drawn below/around the rod so equipment or building portions inside the zone are considered protected under that simplified method.
Detailed Explanation
Concept & Reasoning
Lightning protection systems use air terminals to intercept strikes, down conductors to carry current and an earth-termination system to dissipate it. The protective-angle/cone concept is a geometrical method for positioning air terminals. Surge protective devices serve a different purpose: limiting transient overvoltage on electrical circuits.
How to Solve It in the Exam
Cone/protective angle → lightning rod coverage.
Important Exam PointDo not confuse external lightning interception with internal surge protection.
Related Revision Path
This question sits in the revision path Building Electrical Services → Lightning Protection → Protection Zones .
