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

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.

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.