- has longer life and high conductivity
- is strong enough to allow long spans
- requires more support
- requires more insulators
Answer: 1. has longer life and high conductivity
Explanation:
Copper:
Copper is an ideal material for overhead lines due to its high electrical conductivity and greater tensile strength. It is always used in the hard-drawn form as the stranded conductor. Although hard drawing decreases the electrical conductivity slightly, it increases the tensile strength reasonably. Copper has a high current density, that is, the current-carrying capacity of copper per unit of cross-sectional area is quite large.
This leads to two advantages:
1. Smaller cross-sectional area of the conductor is required.
2. The area offered by the conductor to wind load is reduced.
Moreover, this metal is quite homogeneous, durable, and has high scrap value. There is no doubt that copper is an ideal material for the transmission and distribution of electric power. However, due to its high cost and nonavailability, it is rarely used for these purposes. Nowadays the trend is to use aluminum in place of copper.
