Power lines are typically protected by lightning arrestors that exhibit a very high resistance at normal voltages.

• A. True
• B. False
• C. Not sure
• D. Sometimes

Answer: (A)

Power lines use lightning arrestors that stay highly resistive under normal operating voltages. That high impedance means they draw only a tiny leakage current, keeping power loss to a minimum and the line effectively insulated. When a surge hits, the arrestor’s nonlinear element conducts, creating a low-impedance path to ground and clamping the transient to a safe level to protect equipment. So the statement is true because arrestors are designed to be insulating during normal operation and become conductive only during overvoltages.