Final answer:
The statement regarding high-voltage wires being wrapped in insulating material is false; they are not wrapped but use air and height for insulation. Wood can conduct high voltages like lightning, making it a sometimes conductor. Strong magnetic fields from power lines or permanent magnets can affect compasses and demagnetize credit cards, respectively.
Step-by-step explanation:
The statement that high-voltage wires are wrapped in insulating material is false. High-voltage power lines, such as a 240-kV transmission line that carries 5.00 × 10² A, are indeed held aloft by insulating connectors, but these wires themselves are not wrapped in insulating material. They are bare and rely on air and the high placement above the ground to provide insulation. The ceramic insulators provide necessary insulation from the grounded metal towers that support the transmission lines. This setup allows for the efficient transmission of electrical power over long distances.
Additionally, materials such as wood can conduct electricity, especially when wet, which is evidenced by the fact that lightning can travel through a tree to reach Earth. Therefore, while wood is generally an insulator, it can conduct high voltages such as lightning under certain conditions, making that statement true.
Magnetic fields and their effects are an important consideration near power lines as well. A current in a long straight wire can create a notable magnetic field in its vicinity, which could affect instruments such as compasses. It is also true that magnetic strips on credit cards can be demagnetized if they are placed near strong permanent magnets, indicating the potential for significant magnetic interference.