27. Resistors & DC Circuits
Resistors and Ohm's Law
23PRACTICE PROBLEM
An engineer is designing a lightning rod to protect the equipment of a radio station. The lightning rod, made of copper and with a length of 3.0 m, is placed on an isolated surface at the top of the building. The upper end of the rod is tapered to form a sharp point and the lower end is connected to the Earth. Determine the minimum radius required for the rod if the maximum allowable potential difference between the top and bottom of the rod is 140 V. Assume that an average lightning bolt carries a current of 40 kA and can persist for durations up to 80 μs.
An engineer is designing a lightning rod to protect the equipment of a radio station. The lightning rod, made of copper and with a length of 3.0 m, is placed on an isolated surface at the top of the building. The upper end of the rod is tapered to form a sharp point and the lower end is connected to the Earth. Determine the minimum radius required for the rod if the maximum allowable potential difference between the top and bottom of the rod is 140 V. Assume that an average lightning bolt carries a current of 40 kA and can persist for durations up to 80 μs.