Final answer:
High-voltage wires are not wrapped in insulating material but are held by insulating connectors and air-insulated; thus, the statement is false. Tension is the force in a connector being pulled at both ends, which is true.
Step-by-step explanation:
The statement about high-voltage wires being wrapped in insulating material is false. High-voltage wires that you see connected to tall metal-frame towers are indeed held aloft by insulating connectors. However, these wires are typically not wrapped in an insulating material; they are bare and designed to be air-insulated because the surrounding air provides sufficient insulation at high elevations.
Regarding the concept of tension, the statement is true. Tension is indeed the force that occurs in a connector like a string, rope, chain, or cable when it is being pulled at each end. The tension forces are directed along the length of the connector and pull towards the center of the connector at the ends.